Tips to prevent foot cramps include the following:
Take a warm bath and do some stretching exercises before you go to bed if cramps wake you at night. Avoid pointing your toes while you stretch. Try not to sleep with your toes pointed. Keep your legs warm while sleeping.
Warm up well and stretch before any activity. Stretch after exercise to keep warmed-up muscles from shortening and cramping. Use good posture while exercising.
Drink plenty of water before, during, and after you are active. This is very important when it's hot out and when you do intense exercise. You can also drink an electrolyte replacement drink such as Gatorade after exercise.