imo as far as crickets go i would free range them in the cage till he has been in your care for a while. just make sure you put some cricket food aka gut load i like to use a lots of little bits of different veggies and just put it somewhere in the cage the crickets will go for food before your cham then you could leave them in there over night my cham likes to eat a bunch of crickets first thing after he wakes up and shies out if i open the cage or interrupt in anyway that is what i have seen works best for my cham so you might like to give it a try?
Thanks Franticurchin, let me try this method , will goto get some cricket's food from the reptile shop. The first thing is I need to make sure he does know there's a cricket area .
Cheers