Everyone falls victim to impulse spending once in a while, you just need to make sure that it doesn't get out of control, as that can plunge you into more debt.
Try to determine the difference between wanting it and needing it, and remember your needs should always become before your wants. For example, you might want that new IT bag but your mortgage payment has to come first!
Ask yourself the following questions:
If you have already debt problems then it is important that you tackle your problems