This will allow the rest of the cage to remain from anywhere to the 80's to room temperature. I feel that it's best to provide any reptile with a temperature gradient and let them regulate their temperature. I have problems with undertank heating pads and hot rocks as they don't raise the ambient air temperature in the tank and their surfaces often produce extremely high temperatures. A staple of crickets along with occasional waxworms and mealworms make a good diet. Adult geckos can also be fed an occasional pinkie mouse.
Juveniles can be feed every day and adults every other day.
Supplementation is a must for leopard geckos. Juveniles should be supplemented at every feeding and adults at every other feeding. Gravid females should also be supplemented at every feeding to make up for the large nutritional depletion caused by egg laying. If your geckos don't mind being handled it may be a good idea to feed them in a separate container. This reduces the chance of impaction from ingesting the substrate in the aquarium and allows for you to monitor how much each gecko is eating.