My husband is extremely organized, and I have learned a lot from him. (I've also learned that I love living in a clean, uncluttered, organized home!) Here are a few principles that I have picked up:
*Get rid of stuff. And not just once; do it every few months (we pack up stuff and give it to a resale shop). Have a designated spot in your house to collect and bag up things to give away. Be as ruthless as you can manage. There is no way to be organized if you don't get rid of things.
*Every thing in the house has to have a place where it goes. EVERY. SINGLE. THING. So that means your clothes and also your out-of-season clothes; your wedding china and also rubber bands and twisty ties; library books, incoming school papers, your purse, things that need repair, things to be returned to the store, greeting cards for all holidays, newspapers you have read and also newspapers that you haven't read yet. All your kids' toys have to have a designated spot, and the kids have to know where those places are.
*Go through the entire house, at least once a day. Make this part of your morning or evening routine. Go into every single room, and you will find things that need to get put away. My husband does this, and often finds things that we don't need anymore.
Good luck!
p.s. I used to have a basket in our kitchen that was designated for party favor toys and Happy Meal toys. The kids loved bringing it out and playing with all the little stuff, and it was easy to put away. And it was so nice to have a place for those little crappy toys. (I did sneak some into the garbage every once in a while!)