in my adults tank i use a mix of eco-earth and reptile carpet. in my new babies tank i use paper towels.
i have found my sookeh loves the eco earth a bit too much and makes one heck of a mess. he digs like crazy in it and throws it all over the place lol..
I use shelf liner for all of my tubs. It is cheap, easy to clean, and can be easily cut to fit any tub. Its like 2 bucks for enough to cover 8 16qt tubs (at big lots).
when i first got my leopard gecko i kept her on paper towels, now that she is older and i watch her eat she is on sand (i dont want any hate comments i know the risk that can happen)
Paper towels until i can afford the reptile carpet (college student) =(
i had him on sand for 2 weeks and had to swap it out after he swallowed to much of it when he went cricket hunting
i use reptile carpet for my older leo's,eco earth for my crested and white lines and kitchen towel for my baby leo's my uro whose almost full grown is on play sand