For years now I've kind of operated under an informal shopping cycle. A bit like a farmer's crop rotation system. Except, instead of wheat, maize, barley, and fallow, mine pretty much goes clothes, makeup shoes, and clothes (I don't bother with fallow). Shopping is actually very similar to farming a field. You can't keep buying the same thing, you have to have a bit of variety. Otherwise you get bored and stop enjoying yourself.
Confessions of a Shopaholic (ed. Delta, 2003) - ISBN: 9780440334453