Crickets can be placed directly in your herp's enclosure, or they can be put in a Live Cricket Feeding Rock that allows the crickets to gradually crawl out into the terrarium. This is highly beneficial as it both reduces waste and encourages more natural feeding behavior. Simply remove the crickets from their container, place them in the Feeding Rock, and, after adding supplemental powders to the rock, place the rock in your herp's cage.
After your herp is done eating, be sure to remove the leftover crickets from the tank. This is for a number of reasons. First, the crickets will actually view your herp as a food source (remember, they're omnivorous), and start to nibble on him. Second, they will contribute to the waste products in the cage and make it harder for you to keep the tank sanitary. Finally, having them in there will actually stress your herp.
Mealworms should be fed in a dish to prevent them from escaping into the substrate in your herp's enclosure. Items such as the Exo Terra Insect Feeding Dish are great because they allow your herps to see their food, but they have a shape designed to contain the mealworms. To feed mealworms to your herp, you must first take the mealworms out of the fridge. Allow them to warm up and become active (up to 24 hours before feeding them to your herp), place them in the Feeding Dish, and, after lightly dusting them with supplemental powders, place the dish in the cage.