Take a cooling-off period before impulse buys
If you tend to buy things on impulse, try this trick to exercise a little financial restraint: Give yourself a spending limit, and don’t go over that that limit without taking at least 48 hours to think about it. For instance, if you see a shirt you really like that's fairly expensive, go home and think it over for a day or two before handing over your credit card or spending money you really can’t spare.
A good cooling-off period will give you some valuable perspective on whether you really need the item. Often you’ll realize that you can live without it once the original impulse has faded