Going shopping with my mother growing up I had my own money from babysitting. I would always ask if I could have something she would say you have your money you can buy it if you want it. I would think about it and say no I don't really want to spend my money on that. Smart for my mom though make me use my own money.
As I got older I would go to the store I would want something and I would think about do I really want it. I would think about it as I am walking throughout the store. I would tell myself maybe tomorrow. Well then tomorrow came and I would either forget about it or talk myself into waiting another day.
So, I have learned to sleep on my decisions no matter the purchase unless its like a food or drinks. Stuff that are necessities are a must. Always think a while before spending money like crazy. Take a few days to really think do I really need this?