When I had my firstborn 20 years ago, I went through a lot of trial of error. I grew up in a chaotic house with a mother who was always at her wit's end, yelling, screaming, disorganization. When I became a mom, I knew that at least that particular parenting method was not so great. However, it was what I knew, and I very quickly fell into the same habits my mother had modeled for me. About the time my son was 13 months the chaos began, and I had about 2 years of that before I really found the solution.
Organization and routine. I'm not saying that you run your home like a marine barracks, but you need to have a general idea of what is going to happen when it is going to happen. And the entire family has to buy into it as well. Basically, it's the same sort of thing you see on the Super Nanny show. She was probably a child when I was raising my kids, so I had to learn the hard way! But I kept, and still keep a calendar and routine. When the kids were little, that meant we did certain activities in a certain order... wake up, eating, song time, story time, etc. etc. When they were school age, the routine adapted to that. We had a morning routine for getting out of the house in a reasonably sane fashion, an afternoon routine for decompressing after school, homework, and activities. When the kids were old enough, they participated in developing the routine and schedule. Having the routine, being organized means that everyone knows what the day's goals are, what's coming up next, and can work together to manage time. Picture going to the grocery store. You can start at one end of the store with a list in your hand and shop in an orderly fashion. It gets done quicker and more efficiently that way. Or, you can run up and down aisles in no particular order, getting whatever appeals to you immediately. You'll have a bigger grocery bill and will probably have forgotten some necessary items. It's the same principle.
By keeping a family routine, you teach long term skills of goal setting, time management, teamwork, and consequences. These are skills that will help them be successful adults. And remember our long-term parenting goal is to raise adults, not children! :)
The hard part is getting organized in the first place. It takes a lot of persistence, especially with the children. And, since you WILL have to adjust your routine from time to time, you'll also teach flexibility, as well. Take time to plan what you want to do, have a big family meeting about it... maybe have a family fun night to unveil your new organization plan, invite the kids to comment and accept some of their ideas. Then have pizza and watch a movie or play a game, and make that part of the new family routine, as well. Start with a positive in the routine rather than something like, "From now on, Friday nights will be toilet cleaning night." LOL You get the idea.
I have no problem whatsoever with reward systems. Children are learning, inexperienced individuals. They need to be taught and/or trained. Rewards help bring them back to focus on a task. It's no different than my paycheck! Believe me, I wouldn't focus on my work if I didn't gain something at the end of the day beyond personal satisfaction. I love my work, but I also need to eat and pay my bills! The operant conditioning that someone else mentioned here, eh, not a keeper IMHO. When I was in college, I remember BF Skinner's operant conditioning well. I had more than a few studies on that one. Skinner's observations actually did include positive reinforcement, negative reinforcement, and even punishment. AND, they were applied to animal training, just as Pavlov's little bells were used on dogs. I'm sure a parenting expert or behaviorist developed Skinner's observations into some sort of parenting system. But after 20 years as a parent, I've come to a conclusion about "experts". If all the behavioral specialists were actually doing the at-home with the kids stuff and doing it long-term until their kids were grown and left the house, they wouldn't have time to be behavioral specialists! If you tell a child to do something once and leave them to learn from the consequences, for example, saying "Clean your room," just once, the child will probably not learn that he must clean or live in a pig sty. Rather, the child will learn to accept living in a sty. Lord knows, there are enough "Clean House" programs on t.v. showing grown people living in pig stys. It may work for some families, but not in mine. I don't like bugs and spiders in filthy rooms. And chaos doesn't help a child learn to focus and get a task done. I can't see that sort of thing working well in a house where kids have attention issues or allergies, for example.
Good luck! It sounds like you've recharged a bit and are going to get back on track. Keep at it! And know that no matter what system you use, you'll always have highs and lows. You can get through the low spots. Trust me, I had my fair share, too. If you stay focused on your goal of raising adults, you'll have the stamina to keep teaching your kids how to organize and focus and work toward goals, as well.