For the past year, I put away every $5 bill that came into my possession.

For a long time, I've used the "pay yourself first" trick ... (at least) 10% was direct-deposited into a savings account and we learned to live on the rest (which also included 10-15% of charitable giving).

My only other advise would be to never buy purchases over $100 on impulse. If you still want it after three days, you can find the item again. This helps identify the difference between wants and needs, and also helps you consider whether you want to deal with having another item in the house (you've got to store and maintain most of what you buy).

Lately we've been buying less than ever, selling of giving away things we don't use (try FreeCycle!) and it's nice to not be part of the accumulation crowd.