i like using live plants, its pretty much all i've ever used. well, first of all i use peat moss as substrate. never had a problem with it, although it can mold if the conditions arent right. when i use plants i usually get stuff from lowes or home depot, either the small plants like vines (pothos, philodendron) which usually go for about $3 a piece, or a ficus when you want taller foliage, which usually starts around $7 for a decently bushy, but short one. almost all of my satanics have shown strong preference for ficus. i actually give all my plants a real good washing when i get them because often you find buildup on the leaves you get from these places. i also change out the soil, brushing off as much as possible then transplanting into the peat moss. you never know if the stuff is jacked up with fertilizers or whatnot. peat moss seems to hold most plants well, but unfortunately i have trouble with keeping bromeliads, which i hate because one of my satanics has used it as a spot to lay her eggs. it holds water well and maintains pretty good humidity, you can even cover the top of the peat moss with moss fiber, and it makes it even that much more attractive and i think helps hold the humidity even more. pothos is nice because it fills up the tank and drapes itself over anything, and can tolerate a wide range of light intensity.
right now im setting up my first rubbermaid tank. i cut a big rectangle out of the top and a thin rectangle out of the front, and glued in screens in for a light entrance and air circulation. it's just a real cheap and effective thing to do, i didnt have to go out to buy anything to make it. this tank is going to be less for viewing and more for breeding.
i just plain have a real strong preference for live planted setups. they're just more dynamic than fake plants and give that natural feel. they're really not that hard to maintain either.