Speaking only for myself I have been working on a Jungle theme. A friend and I both are starting Lizardmen at the same time, while I'm in your situation trying to figure out what I want to do, he decided to do a leopard gecko theme on this troops as he recently bought one. I have to say over all they actually look very nice. The advantage of a jungle theme is that you can use things like fish tank terrain to quickly build extremely cheap and durable table terrain that if it gets destroyed your not out a lot of money.
Jungle is Always a go to , if i was starting my army again i would probably be in the same situation, go with a comon thing or try to think outside the box, where would the lizards be able to thrive and survive outside of a jungle? Maybe a swamp or a marshland... or even a lost oasis in the middle of a desert where the skinks have adapted their skin to camouflage with their surroundings outside of the oasis to keep enemies at bay I know its a rough one but its a personal thing , try and create a background and make the colors and bases adapt to your army story.
Jungle is always good for Lizardmen but desert is probably quicker to do if you don't enjoy doing bases a lot.
Personally I am a fan of jungle basing, but I would comb the Itza Gallery for inspiration pictures first before I went one way or the other. Lots of great stuff in there. There are tons of great jungle-lizardmen examples out there with the Maya/Inca/Aztec themes carrying them, but I would love to see a good Pueblo/Mesa Verde styled Lizardmen armies. If you go the desert route, here are some quick examples that came to mind: - @Xasto based his bastiladons in a desert-sand pattern - @Centurion's army from some years ago was Southlands based, but had a great desert color scheme on the skinks. - Lizardmen Army by DezertFox, it was for sale some time ago. Lots of great oranges and basing.
Some good points have been made already. I am always a fan of the unconventional and I think there are less desert themed Seraphon than jungle themes. This is your army so you do you. I just ask that you show us some of your work when you get some models completed.
Really you should look everywhere for inspiration. For example i've been inspired by: - fantasy artwork especially magic the gathering - illustrated dinosaur books - photos of cobras, snakes lizards and birds - buildings - warhammer model colours from other armies ex chaos demons - other peoples models online Really google image search is your friend Start a folder of images of stuff you like and stuff you might want to try. Me I love me my cyan pink yellow lizzies something very neon 80s about them xD