Juvenile leopard geckos (under about 6 months) are growing quickly and should be offered appropriately sized insects daily, dusted with a calcium supplement at most feedings. Sub-adults (roughly 6-12 months) can move to feeding every other day as growth slows.
Adult geckos typically do well on feedings every two to three days, though appetite naturally varies by individual and season โ many geckos eat less during cooler months even indoors. A good rule of thumb for prey size: insects shouldn't be wider than the space between your gecko's eyes, to avoid impaction or choking risk.
Gut-loading feeder insects (feeding them nutritious food before offering them to your gecko) and regular calcium dusting are both important, since geckos get most of their nutrition indirectly through what their food has eaten. Always remove uneaten live insects after feeding time, since they can stress or even nip a resting gecko overnight.