In an attempt to be more frugal in the past saved my pocket change each day and put it into a jar at the end of the day. By the end of the month or when the jar was full, I added it up and deposited it into my bank account. It is amazing how much accumulates that way.
Another thing I have done is to write down everything I spend each day. Often, I will hesitate buying something just so I won't have to write it down. It is interesting at the end of the week to go over the list of things I have purchased and to note things that I REALLY did not have to buy. It helps with impulse buying.