:?: Where does your lizzie live in the wild? If you make its home as much like the place it comes from (within reason) it will make it happy.
My lizzies are desert types, they are happy cos they have a shallow pool to drink from, a hide to sit in when they want to, a rock under a basking spot to sun themselves, a background wall that they can climb with a shelf at the top which gets light from a uv tube to bask without extra heat.
The floor of the tank is covered in wood chippings cos sand was bunging 'em up (swallowing it with crix). Me & my vet think my lizzies are as happy as they can be.
You can tell when they are happy cos they are active and look good. Depressed lizzies have bad colours and drag themselves around with no energy.
Good luck with your lizzies! I'm sure you will make them very happy!