I try to check as much as possible. My relationship with money isn't always the best, so I just want to make sure that I'm not spending any more than I really have to. I kind of want to check it after stumbling across this thread as well.
Whenever I check my bank balance - which is usually about once a week - I go back through my purchase history to see if there is anything suspicious. I do online window shopping, and most of the time when I do buy stuff online it is through gift cards (only a few times through debit or credit cards).
I check at least every Monday, but I tend to check a bit more than that in some cases. I've got a few bank accounts so sometimes it's all about juggling the money.
My bank sends me e-Statements to my email monthly so I read them every time I get the notifications. Just in case there is anything wrong with my number and figures, I'd be able to report it immediately.
