A humid hide is a pretty good place to start. A hunk of sphagnum moss in one of the hides that you moisten frequently will work wonders for your humidity. You can also provide a large bowl of water in your setup if you honestly believe your snake enjoys the soaking. I have an oddball who loves to soak in his water bowl (even if he is quickly outgrowing it). His setup is identical to the other 3 snakes in the same sized tub as him, and a scaled-down version of my bigger tubs, no mites or other bugs, and it's only him that soaks. It's possible I'm missing something with him, but the best reason I can tell is that he just likes it. I still wouldn't take him out to soak him, but if he wants to do it himself I don't mind.