One place to start could be looking at some of the specific ways you feel your kid is being "defiant" and look for a positive way to reframe what you're seeing. Maybe he's someone who, for instance, always thinks for himself... even when you rather he just do what he's told ;) Maybe he's someone who has definite opinions and learns by bouncing those opinions off the world and seeing what happens. Maybe he's really very sensitive and tries to stand against anything he sees as injustice. I don't know your kid, so I'm just tossing out examples.
My kids are very strong minded and tend to learn experientially - which for them can mean forming theories and testing them. Seen from one perspective, that makes them "defiant" - they're not the sort of people who do what they're told, unless it's convenient for them. That's not a result of unschooling, although the fact that my stepson is that way led us to unschooling. Life got so much easier and sweeter the more we became open to the idea of helping him explore the world in ways that worked for him rather than "helpfully" telling him the "best" way - he didn't want our answers, he wanted his process.
And my daughter is similar - as a toddler she never asked what or how or why, she said "because..." and explained the world to us. She wasn't always right, but you couldn't convince her of that. It was so much better to let her have her certainty - amazingly, she didn't mind having the world prove her wrong. She just didn't want to be told. Like she didn't want the spoilers.
She also has some sensory issues - which I've discovered a lot of parents read as defiance, so it's worth mentioning in case it's an issue for your kid. A lot of the time when kids are "refusing to act right" or "making a scene" or "trying to get attention" they're really reacting to overwhelming sensory stimuli - whether that's a misplace seam in a garment, or the texture of a food, or the acoustics of a room, or any of a thousand other things. And no-one responds well when they're overwhelmed :P Happily, it's possible to help kids to deal with the world without being overwhelmed by it, but it's a process that actually starts by helping them find ways to minimize or even avoid the too-intense stimuli in the first place, so they can learn to deal with the world at their own, unique pace.
There are several different issues with the idea that your teens are "lazy". The first is that it takes a good bit of time for kids to re-learn how to self motivate! School - and often homeschool, too - strips that away from kids. "Deschooling" as it's called takes months - for teens, expect nine months to a year, and know that, depending on how big of an impact school had on them, it could even be longer. :( It helps to imagine that your kid has had a serious long term illness and needs time to recover. Let them chill and recuperate. Hang out with them. Watch some shows and play some games together. Gently offer to do fun things together, but don't push. Take time to get to know each other in a different way than before.
Another big thing to know about young teens, though, is that the big developmental processes going on in their brains takes a lot of energy! They may need a lot of down time, time to ponder, time to daydream, they may even sleep more. Around the online home/unschooling community at large, this has been dubbed a "cocoon stage". Not all teens "cocoon" but many do.
But the other thing to keep in mind is that natural learning won't look like school learning. It will look like kids pursuing their own interests - even their non-academic interests. Things like doing hair and playing video games. So it will help you and your kid for you to treat those as "legitimate" interests from which they will, inevitably learn. There's plenty to learn! And it doesn't need to be directed toward any particular goal. School sets you up to think there's this big race toward a finish line, but it's not true. It's really okay to give your kids a chance to breathe and discover who they are and how they learn, naturally.
Something that comes up a lot in the autonomous education /unschooling movement is the way kids learn these kinds of skills without necessarily being taught. And often the ways they learn them are by doing exactly the sorts of things that parents and teachers commonly try to limit. There's a disconnect in adult expectations between the skills that we want kids to learn and the way we want them to learn those skills.
So parents will panic when a kid shows good attention span or focus when those aren't directed at chores or school work (Kohn mentions worthy subjects). Or worry when a kid keeps trying and failing at a game over and over, maybe crying and swearing, but persisting. Or when a child insists on using Just these materials in Just this way to do a project. Or creates a detailed plan and wants to stick to it, despite obstacles. When kids do those things independently - self confidently pursuing their natural curiosity - it's often seen as problematic.
Organic learning, often called radical unschooling, is a really different paradigm of adult-child interactions. Its challenging to envision relationships outside a model of limits and testing and adult-based decision making - it sounds wacky. How can you have relationships without limits? Craziness.
Start someplace else. Start from ideas of exploration and autonomy and connections. Human beings are all about exploration and autonomy and connections - especially children.
From a radical unschooling perspective, children don't need limits in the sense that conventional parenting assumes. Limits are a natural part of life - the sun goes down, flowers fade, moms get tired, people miscommunicate. Natural limits. Organic learning isn't about ignoring those or pretending they don't exist, its about finding ways to facilitate all that exploration and autonomy and connecting over and around and through the limits. Limits aren't the tools we use to manipulate the world and each other, they're the playground equipment we get to climb on.
The nature of natural consequences
People getting frustrated and angry at one another is a natural consequence. Its not always reasonable! but its certainly natural. That's something families can talk about and problem solve around. One of the things that can lead to family members getting frustrated and angry is "disrespectful" language or behavior - but making a rule against it doesn't keep people from finding ways to be snarky at one another. Similarly, parents often get frustrated and angry by young children running away, but making a rule against it doesn't guarantee a child won't run, or find other ways to go somewhere or do something a parent dislikes.
Rather than making rules, start from the underlying reasoning. What do you want to see in your family? Be that. Young children are often said to need concrete ideas more than abstract - they need to see and touch and smell courtesy and grace, not be told about it. They need to experience win-win problem solving first hand, as a real fact of their real lives, not hear about cooperation. They need to see mom take a big, deep breath and hear her say "okay, I'm really mad now and that makes it hard for me to think" rather than "I'm the mommy!"
Forget rules. Forget authority. Dig deep down and lay out all your most basic values and try to become them.
Value based parenting
If you value authority, then embrace authority. Be the best authority you can be. I don't value authority, so I can't say much to that.
One of my values is kindness so I strive to be kind to my loved ones. Another is thoughtfulness, so I try to be thoughtful. I value trust, so I work on being trustworthy in the eyes of my children. I value joyfulness, so I strive to live joyfully, every day.
The biggest issue I have with an idea like "respect" is that it has a whole bunch of values and cultural memes all rolled up together. I found, in my own search for my basic values and how to live them better, that when I broke "respect" down into bits, I didn't really need it as a concept. I can work from the parts - which include things like thoughtfulness and trust.
My personal experience is that my kids are more likely to be kind if they have received plenty of kindness lately. They are more likely to be gracious if their needs have been met, if their "cups" of love and attention are full. My kids are most demanding when they feel a sense of lack - isn't that when we All are the most demanding? when we haven't had "enough" sleep or care or time or loving? Its good for parents to look for ways to get their own needs met so they aren't parenting from a sense of lack. Its sooooooo much easier to do all the warm-fuzzy stuff from a place of abundance! Getting to a feeling of abundance without turning it into a battle of my needs -vs- the kids' needs takes some practice, and is definitely more challenging with babies and very young children, but its possible!
It may be that your kids are happy to listen to your decisions - some are! And if so, then all this problem solving for other ways to communicate with children probably don't make much sense to you - why not just tell them? Individual temperaments and personalities have a lot to do with this. Some kids need to be listened to for a long long time before they can do much listening. Some kids need to make as many decisions of their own as possible before they feel safe trusting someone else's decisions. Some kids need a thousand small acts of kindness and service a day to feel okay about being in the world. In conventional parenting, those are "problem children". In unschooling families, they're our children, and we honor their needs and look for ways to help them meet them.
Living for today
My stepson, Ray, has only been a part of our unschooling family for a year and a half. In that time he's gone from being "the typical surly teenager" to a very gracious, sensitive young person - so I don't believe all those rules and demands that he respect authority did him "undoable harm". Humans are resilient. We grow and we heal.
As refreshing as it is to know that, at the same time, that kind of thinking ignores the reality that is our children right in this very moment. In this moment, I have the opportunity to be a gentler parent, to be more thoughtful, to make my children's lives softer and warmer, to fill their cups of love and attention a little more. That opportunity is why I decided to have kids in the first place. I could fall back on what "everyone knows" about kids and parenting, but that doesn't uphold what I really value in my heart of hearts. I value my kids for who they are right now, and want to find more and better ways to honor that right now.