A small dish of water or keep misting. hmmm what to do what to do..
I think try the dish & see if it helps but I also think it depends on where you live..what your climate is like.
Where I am in this desert it would take both, a dish & misting to keep it humid enough.
I have a pacman frog living on moss & I have to pull the moss out & soak it, not mist it every other day or else it's as dry as a bone & that's WITH a water dish inside the tank with him. Of course his UTH has something to do with that, I have to keep him warm enough too.
He likes humidity at around 75% I have to keep an eye on that because in no time at all it'll drop down to 40% if I don't keep wetting down that moss.
So what I'm saying is you just have to adjust it to your particular climate.
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PHRatz