Are you running bad due to poor play or bad beats..it's hard to say sometimes. It's difficult to be completely objective about your own play. Try and set yourself a Loss Limit of a certain number of buy-ins for a day. The amount/number depends on your
bankroll and normal volume of SNGs played, but that seems to work for me. Sometimes if I think I'm getting too spewy in SNGs, I'll blast off some points(FPP/VIP) buying into MTTs. I find this causes me to gear down and then I can go back to sngs. If the opposite is true and your are being too passive or even nitty, I'd just quit for a few hours or the day.