Setting goals needs to accurately reflect what you are capable and willing to do in your spending. There have been a few times when i was a little zealous on cutting back and just couldn't keep up. This can be discouraging. The following are categories that Dave Ramsey (my financial hero) uses to describe how much you should be spending and where. Remember that their isn't one fix all. Depending on your income level and location your figures will probably look different, but this should give you a ballpark of what is reasonable in every area.
Expenses
Range
Charitable gifts
10-15%
Saving
5-10%
Housing
25-35%
Utilities
5-10%
Food
5-15%
Transportation
10-15%
Clothing
2-7%
Medical/Health
5-10%
Personal
5-10%
Recreation
5-10%
Debts
5-10%