I hate those. I get those cramps in the mouth when I yawn sometimes. You can try taking multi-vitamins that have potassium in it daily. I personally use Animal Pack. Or you can buy potassium seperately. You should take a multi anyway, so I would find one with that included. Also, I wouldn't shy away from a banana at certain times of the day, but only first thing in the morning with protein, or right after a workout, which the simple carb is most likely to be burned off, and helps to shuttle protein quickly to ur muscles. That's the only time that I would consume a simple carb like that.
Also, taurine is supposed to help with cramps as well.
Below is a site with different foods rich in potassium:
Potassium Rich Foods - list of Foods High in Potassium