Put Camphor between the mattress and the bottom sheet—stops you getting cramps though the night—however IF you get them through the day—
Make this up— I was sceptical—but it really works
Put some lemons cut in half in a bottle cover with Metho—let sit for 2 weeks (with lid on) after the 2 weeks take out the lemon and squeeze the rest of the juice into the metho—and discard the skins—if you do get a cramp rub some of this into the area—you can feel it disappear.