Depending on how big your chameleon is going to be
-add lots more plants, live plants are the best option as long as you use organic soil and cover the exposed soil with big flat rocks, I love pothos because they thrive under the reptile lights and constant misting, they also grow very fast and are useful when your trying to create hiding spots for your Cham-
- use wire ties, fishing line, or even thumb tacks to hold branches horizontaly across your cage, dragon strand sells these ledges that you screw into your cages frame so you don't apply too much stress on the screen.
-use real branches, just wash them off before you place them inside your cage, the bark is great for your Cham to grip especially when wet, get different size thickness for your animal to grip
-make sure you have adequate uvb lighting, please use a linear bulb, they give off a more broad amount of light for your Cham to benefit, also use the proper wattage basking bulb, buy a thermometer that has temperature and humidity probes so you can be checking both.
Good luck!