Here are pics of our two tanks. We used Repti-carpet instead of towels, but it's hard to keep clean. Also, we added a background on the outside of the tank to kind of make it look more finished. The hidey rocks are just the typical ones from Petco or similar stores. We also like to put a statue in all our tanks (geckos and hermit crabs). Since our geckos have Egyptian names, we put a cat Goddess statue with the girls and a Horus statue with the boy.
20L tank with our male, Ramses:
40g tank with our girls, Nephie & Cleo:
In the girls' tank, I had leftover background paper that I wrapped around the moist hide tub (which started out life as a Risotto container

).
Of course, they're all sleeping right now so there are no geckos in either picture. Typical!