[header] How to care for a crested gecko [title] Set up a large terrarium. [step] Crested geckos are arboreal, meaning they live in trees, so make sure to get a vertical terrarium. Cresties will love having some space. 
If you're starting out with a baby gecko, look for a 10 gallon vertical glass terrarium at a pet store. If you have an adult gecko (or once your baby grows up), get a 20 gallon one.