Unprinted news paper. I have a rack system and one roll last two months+. Super easy and fast to clean. Easy to spot the mess. No little shavings over the floor and does not mold. During shedding, the snakes gets moist paper towel to up the humidity. Simple easy and to the point.

If you are wanting to make a nice looking enclosure though, best thing IMO is cypress mulch. It hods humidity, looks nice and hides smells.

Eco earth or coconut husk are also really good options but the problem with them is if the dirt stays moist too long, you risk scale rot. It also makes it really had to sanitize a glass tank as it tends to stick to the sides and gets in the corners.