I usually don't raise on blinds either but, if there is an unusual amount of players calling and I have a hand that has potential I will raise at least double the blind and in some occasions even more. Like slinky said I will usually only do this if I have one of the blinds. Also depending on how the cards are treating me if I catch a high pair in the hole I will go all in and try to run everyone out. Sometimes it works and sometimes it doesn't but then again that's why they call it gambling.