I just record all my discretionary purchases in a spreadsheet and recoil in horror at the end of the month. My monthly spend has been steadily dropping since I started doing this about six months ago. EDIT: I seem to have misunderstood the topic of this thread, but, as another commenter puts it, the best way to save money is to not spend money in the first place.
my simple way is take the misc. expenses $ money right off the top when cash check. i put the cash in my pocket. $800 every two weeks. and i use cash for all misc. stuff. use the credit card for fixed monthly expenses and pay maintenance stuff like insur, etc elec. check. so if run out of cash then done till next check. and usually have left over dont usually spend full $800 i just throw it in the drawer until it piles up and then spend it on something or divert to invest. acct.