It depends a lot on your conditions and schedule as well as species. For example, when I had a lowland terrarium upstairs, I had to cover it because the humidity in the room was low, so I used a mix of 1/1/1 lfs/fir bark/perlite and watered about once a week. Then I moved it into the basement where it's naturally humid and I only cover the tank half way, so the water evaporates faster and with the same mix I had to water every 3 (that was pushing it!) days. Since then, due to my schedule I had to replace the media with straight LFS and now I have to water once ever 5 days, not pushing it.
So, depends on the species, your personal schedule and the conditions. I'd still use 1/1/1 lfs/fir bark/perlite if I didn't have to be out of town for 5 days at a time.