I built a drawer with plywood and lined it with 1/8" plexiglass from home depot. I could not find a tray that work so basically had to make my own. I posted a picture of it in this thread.
I transformed an old entertainment center into my chameleon cage so the bottom is wood, no drainage but I put down some vinyl tiles so the water dries right up.
Painted (zero VOC acrylic latex) wood. I dont do a lot of misting (primarily they drink from drippers) so there's not a lot of uncontrolled water to deal with in my cages. Have floor tile on the bottom of a couple.
i guess it all depends. if you use substrate, alot of people use hydroton clay balls for drainage. i've built my large viv with not too much planning, it turned out super sweet, but no draining system. i do plan on hooking up a MistKing in the near future and with all of the substrate i have, i dont think two 45 or even a minute spray a day would leak. if you have an all cage with a potted plant, than as most have stated, a drip pan is what is used.