This is the cold side of my vivarium. I have made the rocks to form a cave to act as another hide. 
 This is the warm side of the vivarium.
 This is my leopard geckos vivarium. The size of the viv is 24x18x17.5 and that size is fine for housing leopard geckos.
I use sand as substrate. I know people say not to use it as it can cause impaction, but I have used it for years and had no problems. Sand is fine as long as you use it correctly, but I will explain in more detail in the leopard gecko care sheet page.
I have 1 exo terra hide and the rocks create a place for climbing and also a cave for them to hide in. I made my humidity box from foam, and I use vermiculite as substrate for that. I have a water dish and calcuim dish. This setup is perfect for leopard geckos, as mine are very happy.
This is my other leopard gecko enclosure. This is the warm side. 
This is the cold side of the enclosure.

This vivarium houses 1 male a 1 female, it has 3 hides. The warm hide is the exo terra large hide, the cold hide is the exo terra medium hide. Our third hide is our homemade humidity box. The female will use this to lay her eggs.
My viv's size is 34x18x19. This viarium could house approx. 1 male and 3-5 females.
This is my veiled chameleon vivarium. The size of the viv is 18x24x17.5 which is fine for chameleons as they need tall vivariums instead of long ones. I use reptile soil as the substrate as it looks very natural. I have 7 fake plants and 2 live plants, that gives Isha (the chameleon) many places to climb and relax. The small live plant acts as a basking spot which I have a 60 watt red light over the top which provides enough heat for the chameleon.