I use high-quality fish tank plants in my leopard geckos tanks because there aren't that many plants I can think of that can take the high heat, dry climate. Cacti are OK but its hard to find nice ones that aren't spiky.
Jade, snake plants (Sanseveria), caudexed figs, aloes, small pony-tailled plams, Haworthornia, Snake plants (sanssevieria), , philodendron (a succulent), climbing aloe, & Consolea falcata (a cactus) are supposed to be OK. I know someone else that has used African Violets and says they're fine...but don't quote me on that!
BUT people have warned me that while some succulents may be thornless, they emit small amounts of sap...the geckos don't eat the sap but crickets might and when the leos eat the crickets that have ingested the sap, it can harm them.
I personally do not think that aloe is bad. Many people use aloe in their leo tanks...and succulents...and thornless cacti. Many people. I do think its probably safest to have the plant in a pot or something that is slightly higher than the geckos' eye level though.
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Use a plastic container for the moist hide. Its the only thing that works well enough to create the necessary humidity. You can then get creative and glue stones, fish tank rocks, moss, etc to it to disguise it...or glue some slate together and make a hide to go over the humid hide as a cover.
I use "disposable" tupperware containers. They come in packs so you can make many and if you screw up the first one, just start over!

I'm lazy so I didn't get very creative with these. I just threw some stuff on top of the ones in my 'viewing tanks'. These ones were in rooms where people can see them, not hidden in the basement/garage...so they had to look OK. I have seen some very disguised ones that other people have done.

Here's a picture of one of my banded geckos' humid hides -- they are a lot smaller than a leo. My C.A. loves his hide! I put sphagnum moss on top of the hide to disguise it a bit:

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Too many Leos
1.0 feline "Spot"
0.1 canine "Tika"