Preteens are at a particular stage in life that makes them very different from their younger selves and very different from adults. That means they are often motivated differently so your question is exceptional in its likely quality in terms of others needing similar advice.
The first thing to know is that at this point in their development, teens are actually having a growth spurt in their brains equivalent to the one they had when they were between two and five years old. They are not growing new cells, but the are growing new synapses (or connections) between the cells they have as well as a myelin sheath over the cells in their frontal lobes. Sometimes, things they could do only a month ago are actually difficult for them now because they honestly get muddled and forgetful at times. This doesn't excuse things like not getting work in, but it makes it a lot easier as parent to be a little more patient about it. If the trouble is organizational or related to things like picking up or turning off lights etc. Talk to them about their brain development and use things like planners, calendars and to-do lists with them. Einstein didn't learn his own phone number - this genius' explanation, "I have enough to remember already." He could look his phone number up if it was written down and he knew which book to use. Work on teaching them to use methods that require less memory.
Teens and pre-teens also have a lot chemically going on (changing and raging hormones) that in an adult would be enough to cause us to be diagnosed as clinically insane and prescribed drugs to help moderate it all. They are learning how to balance all of this when that myelin sheath is still growing and their brains aren't really built how to moderate emotion yet. This results in back-talk, fit throwing and a host of other super wonderful parent favorites. Take a deep breath, remind yourself that, "this too shall pass." and then try to use empathy. Even though they are not yet adults, they really want to be treated like adults. They need you to listen, empathize and understand not to yell and lecture. It is often more effective to acknowledge their feelings, listen, paraphrase calmly and then calmly state your concern. Follow your statement of concern with a question - what does your child think the answer is? You may be surprised to find they know what is happening is wrong and may even suggest a punishment more harsh than you would have thought to give yourself. Or they may express a need for help and how they can get that help from you.
Instead of using punishments or rewards, continue to focus on finding the natural consequences. For example, when a child doesn't turn in their work, their grade suffers. When a grade suffers, so do future prospects for further education and careers. If your child wants to live a vagabond kind of life, let them live it. People who aren't gainfully employed don't have money to stay "in fashion," go to the movies, hang with friends, by cool stuff like the latest i-pad, i-pod and i-phone. Don't warn, threaten and cajole, just take the privilege away and describe the connection in one paragraph or less coupled with empathy. "I'm so sorry that you haven't been taking care of first things first. It is such a bummer you can't go to the theater tonight, but people who don't get their work done, don't have money for such frivolous things." Don't argue, don't worry if they pout, just repeat yourself and walk away - they'll get the point.
Teens also need something that is "theirs". A way to stand above the crowd in a positive way. Does your kid have an outlet that is related to a special interest or talent? At parties and such, adults are identified by their careers and their special interests. Teens want this too so if they have it don't take it away and if they don't, help them find it!
It also may be that they need employment. Do you feel good about yourself and at your best when you aren't productive? If they can't get formal employment right now, why not pay them for a "special job" that will use their best in your home? I'm not talking about paying for chores here, give them something that wouldn't be the average kid's work for the family anyway. **Or **find a volunteer situation that gives them real-world experience in an interest area.
See this article for more, similar ideas.