Im going to be getting some leopard geckos next week, my dad has a couple of them and how he feeds them is he feeds them both crickets and mealworms.
When they were babies he alternated the type of food each day, for example he fed them crickets one day, mealworms the next day, and I believe he fed them as much as they would eat within a certain time limit, like 5 minutes or something like that.
When they got to adults he fed them the same way, alternate food but every 2 days so one day crickets/locusts then 2 days later mealworms.
When they were adults he occassionally gave them a pinkie mouse as a treat.
I am planning on following his feeding technique, he brought them 14 years ago and they are still here.
Hope this helps