You can change the substrate to cypress mulch, coco husk, coco fibre, or a combination. These substrates hold in humidity quite well. There are probably other ones as well but those are the ones I know of just off the top of my head.

Another thing is making a humidity box by adding damp sphagnum moss inside a container. You could also add damp sphagnum moss and place it in different areas of the enclosure.

Regular misting could be good enough for some people, but from the sounds of it, I would add regular misting to whatever other method you decide to use.

You could also place damp towels on the top of your enclosure. However just make sure it isn’t underneath a heat lamp, because that could cause problems. The dome/cover of your lamp should be level to the towel (if that makes sense) to prevent a fire hazard.