With 3 kids, I have to be in a constant state of purging. I keep a box in the bottom of my closet. When I encounter clothing that's too small, or a book which is "too young", I don't wait--it goes straight into the box. The box goes into the garage for the next donation pick-up.
If you have a food processor and have access to fresh dry roasted peanuts, you can make your own peanut butter. Just run the peanuts with the chopping blade... it may take a few minutes, but it will get there. It tastes fresher than pre-ground natural PB, and it's probably cheaper, too.
Ride your bike instead of driving whenever possible--commuting to work or school, running errands, etc. It often doesn't take much more time than driving, and it's a good way to squeeze in more exercise. Bonus: saves money, good for the earth!
If you don't buy it, you can't eat it! If you can practice discipline at the grocery store--by not buyingunhealthy food, you won't have it at home. This will put you one step closer to achieving your healthy eating goals. I try to be very focused and stick to a list when grocery shopping.