Make sure the tank is escape-proof. If there's any hole that he'll fit through, he'll find it and use it.
The temperature should be room temperature in one end and higher in the other. I'll let someone else tell you the Fahrenheits.
Crickets aren't okay and neither are any other insects. Try earthworms, fish and pinkie mice.
The water should be in a bowl, nowhere else. Any fairly shallow dish will do.
They need to be able to hide, it's best to enable it. The safer they feel, the more time they'll stay visible, though.