I saw some pretty good plans for one from Chameleonjournals.com
Go there and click on "market place" and you can find the instructions there on how to make one and modify it to your needs. Their's looks pretty good. Or you can just come up with your own design or look at other owner-made cages in the photo gallery or on the internet and get inspired.
I've just decided the best way to go is by using 1/2" x 1" PVC vinyl coated wire mesh. It's easier to build a cage with. All you need are rings to clamp the panels together. Or you can even use thick industrial zip-ties.