Never spend money you don't have. Always know where every cent you have goes. Track expenses for 30 days, every last penny and it is amazing how much gets spent on coffees, or a quick snack. Take your lunch, take coffee in a thermos--flavor it with a little vanilla if you want something fancy.
Clean out the things you do not need, have a yard sale or sell some of the things on Ebay.
Shop only with a list and keep an eye out for some good prices. Make a game out of it. Take your weekly grocery budget with you to the store and try to come in under that dollar figure and take anything you do not spend, whether $1 or $10 and put it in the savings account.