Try to find what hits and stay with that bet and you'll get good playing time. Some machines will do great on the higher bet, some on the mid bet, and many on the lower bet.
It depends on the machine and location of the slot in the casino plus your bet. Even at WinStar, you're probably going to find a machine that just won't give. We have toured the country and been to many casinos and honestly they are all the same.
