increasing humidity
of course more large dense live plants will help raise your humidity for a brief time window after misting.
if you are looking to raise and stabilize your humidity on an ongoing basis, this can easily be accomplished with a small $ expenditure, assuming we are talking about starting with a normal aluminum frame screen cham cage, and you are at least a little handy with tools
with less than a couple of hrs work you can easily modify your cage so it is similar in concept to a SANDFIRE DRAGON RANCH "CRESTED GECKO CAGE"
http://www.sandfiredragonranch.com/index.php?main_page=product_info&cPath=10&products_id=87
basically, this involves making cut to fit plastic panels that are screwed to the cage frame with small stainless sheet metal screws, so that you end up with a cage that has clear or white plastic sides and back panels but will still leave you with the front of your cage unaltered.
depending on the specifics of your cage const. (and your tool skill level), you can put them on the inside or out. you dont have to do all 3 panels, just doing the back would help some, but doing all 3 panels will significantly increase, and stabilize your humidity, sfdr "crested gecko" cages are great for neonates and any chams requiring a boost in humidity. the cage will still need to be well planted and misted regularly for the modification to have an effect. otherwise your ambient cage humidity is likely to just be whatever the humidity in your room is.
first view the link and decide if its a mod you are comfortable with.
if you decide to do it, you can use 1/16" plexiglass but it is quite expensive, but there is a cheaper alternative, the acryilic light panels that are intended as a lens for in ceiling 4' fluorescent light fixtures are fairly cheap about $5-10
depending. the only drawback is they are usually only 22" wide, so depending on your cage size and construction details you may need to flip them sideways and use more than one piece per side.
once you have your pieces cut to size, just tape them in place inside or out depending on your cage construction details and preference. once taped in place. just determine where you need screws (must be able to screw into cage frame) mark your screw locations and just drill through the plastic and the first layer of the cage frame with a 1/16"drill. then install your #4 stainless sheet metal screws, remove the tape and you are done.
you can put them inside or out depending, there are +/-'s to both
you can use clear, or white , i prefer white, makes a great photo background when contrasted against the color of your plants and your cham, dont used the cracked the texture can complicate the install and dont use black or it will suck the light right out of your cage. be sure to size your screws according to the thickness of your panels and cage frame, you only want to go through the first part of the frame not clear through, #4-6x1/4" inch is usually what i have used.
if you prefer to install on the outside of your cage you can save $ by using smooth white plastic bath panels that are usually about 1/8" thick , the faced white side is pretty water resistant and they come in 4x8' sheets for usually around $12 so that drops the price considerably.
if you feel this mod is important but dont have much cash, you can accomplish virtually the same thing by just neatly taping heavy clear visqueen around the back three sides of your cage with gorilla tape, the down side is that it usually doesnt look as neat. also the visqueen cant hold up to the uvb, so you may need to redo it every 6mths to a year. if you decide to do it and you are having probs, feel free to pm.
if you wanted it to be exactly like sfdrcgc, then you would need to completely disassemble the cage (notice how they have the panels sandwiched between the cage parts), you would also probably need to use slightly longer screws. also the distance between the door and the side of the cage will increase by the thickness of the panel, so you would need to reposition the hinges and maybe even go 1 size larger.
like ep's have said there are also other options like just get a cool mist humidifier, about $30 (not a steam humidifier) just turn it on and point it at the cage , you could also get an ultrasonic humidifier, about $45 put it on a digital timer that has 20 cycles per day, about $15 and just run it for a minute or two each cycle, ultrasonic humidifers produce an instant COOL steam like vapor that will instantly raise the humidity of any small area or even an entire room. i have found walgreens to be one of the better places to buy humidifiers.
imo, generally speaking, hydration is more of an issue than humidity, jmo