I haven't found anything that can help besides a humidifier if you live in a low rh climate. I've used bowls and buckets of water, wet towels. Maybe throwing 50 humidity packs in there. Haha with 50 to 70% you're good tho. I've grown with no humidifier the whole grow personally that's been years ago but I dont remember it making that much of a difference. I only use it now because of reports of higher humidity making vegging plants happier vpd or whatever it's called.
I live in southern new mexico our rh is usually 15% round about. I grow outdoors as well the low rh has never effected them from what I can tell
Its 19% rn both autos California orange and a white fire 43