I actually built foamcore garment racks that I could keep on the shelves in my closets and hung the clothes on balsa-wood torso-shaped hangers I made myself, at least for women's clothes. Menswear I actually had to buy doll hangers and various kinds of clips (tiny clothespins work great). Twelve inches long inside (so I didn't have to cut the dowels that came in the pre-cut package), four inches wide, and the height varied depending on what I was hanging, they slid in and out like books and made my closet look VERY tidy. I don't know if it's the most efficient way-- overload one of my racks and the dowel would pop out, I re-glued them a lot-- but it kept all the clothes organized and wrinkle-free, and I could hang two-piece outfits together.

And they were fun to build, but I like building things.

I do still sort of use the torso-hanger idea for Monster High, but instead of being hangers they're just... flat paperboard torsos that I put the outfit on to keep it together, then all the outfits and shoes and sturdy accessories go in a ziplock baggie labeled with the character's name. Jewelry and sunglasses and things go in these, because I can sort by character and just... dump everything out when I need to see it all at a glance.