I do very little for humidity except monitor it, for most of the year. If shedding appears to be a problem, I then use a spray bottle (mist) to increase the humidity a little bit next time that snake sheds. I have one snake that I have to regularly increase the humidity for, and 4 that I don't, except in winter when the humidity drops to 10%.
I have one baby who sheds every 8 weeks, so don't panic if 6 weeks go by without a shed. I just watch to see that they are out and about in their cages in the evenings unless they are digesting, and when I don't see them out for 2 or 3 nights in a row, I know they are getting ready to shed, and then I don't feed or handle them again until they finish, about a week or 10 days later. I keep track of it all in a log so that I can know when to expect it next. I don't just watch for them to look blue because I'm really bad at seeing blue on my lighter colored snakes. It's really obvious on bright or dark colors though.