Building a home for your lizard - choosing a soft ground covering
When you're housing your reptiles outside, the substrate, or material that covers the bottom (ie. that they walk around and sleep on) is especially important. In particular, you want the substrate to be a soft material so they can dig and keep their claws trimmed. While this will help the lizard's hygiene, it should be noted that softer materials are more difficult to clean.
What ground covering to use (and not to use)
Unless your reptile is a native sand species, we don't recommend using pure sand or gravel - as your lizard will often eat some of the substrate, and sand and gravel aren't optimal for digestion as you can probably imagine. You should also avoid peat (dust) as you don't want the ground particles to become airborne and cause breathing issues/ lung damage. Use a mixture of sand, mould, and bark chips instead.
How much ground covering?
The depth of your substrate covering should be at least 30 centimeters, but don't go overboard. If you use too much substrate, your ground cover will retain excess moisture and cause an inbalance in the humidity level. Speaking of humidity - for tropical lizards species it's a good idea to keep your ground covering damp.
Furnishing your reptile's home
When housing your reptile outside, it's important that you furnish their cage appropriately. You want to give them plenty of opportunities to climb and hide, given the changing conditions of an outside environment. When picking stones and wood, use smooth stones, and try to use at least one large flat one so they can lay out and bask on it in the sun. You'll also want a shady area where they can go to cool off when needed. Bottom line, there should be a gradient of temperatures in the cage that allow them to warm up and cool down as needed (ie. regulate their body temperature). Finally, with regard to climbing structures - try and give them ledges and overhangs similar to what they might find in a natural environment. This will help them move and get exercise, as well as feel more at home. Bottom line, make sure all your "furnishings" are solid and fixed in place - you don't want your reptile knocking over a rock and getting squished under it.