This really should be a sticky! There are so many factors for humidity and it would be great to get them all into one post. I ended up covering 3/4 of my screen top with plastic wrap to combat dry winter air. I used to tape the plastic wrap to the outside of the screen top but a few days ago I stretched the plastic over the top and then put the screen top over it. That seems to keep it on there good and prevents the screen from getting wet (I had some small rust spots).

Plants and moss are a great way to improve humidity if it's a big problem. Running water in the tank can also be helpful (waterfall, fountain etc). I know that an automatic misting system is ideal, but the truth is, it's quite an expensive investment that not everyone can (or will) make. It is something that I would like to have in the future but as of right now, it's not possible. I'm only gone about 4 hours out of the day on most days so I'm just super vigilant about misting while the air is super dry!