My (hypo)manic spending is usually impulse when I'm out and about. I keep my credit card and my debit card locked up and don't carry them around with me when I go out so I'm pretty much limited to buying things in cash which I don't have a lot of on hand either. It also helps me to have plans with the money like "I'm going skiing so I need $29 on me on Wednesday so if I want to go skiing I can't spend any"