A few questions...

Okay, I take care of a few leopard geckos at my university, and I'm considering getting my own leo soon. I plan on housing it in a tank, and I'd like it to look nice, so what kind of substrate could I use besides tile or paper towels?

Also, what size tanks are suitable for adults, gallon wise? 15 gallon? 20 gallon?

Thanks in advance!

Tile and paper towels are really the best options. Carpet's not great because their claws get caught in it. Basically, if you can find something they can't easily ingest which is not going to catch their claws, you'll be in good shape.

As far as tank size goes, adults do great in anything from 10 gallons up to whatever size you feel like taking care of. Anything larger than about a 20 gallon is going to need lots of clutter and lots of hides in order to allow them to feel secure, but there's really no upper limit to tank size, assuming you can meet the husbandry requirements and keep it clean.

I keep my adult female in a 20 gallon long (30 inches x 12 inches x 12 inches) and she does great.

Thanks, yeah I found some pics of cool leo enclosures last night and I think I might end up using tiles.