I have three hollow back half body forms, children's, 'normal'. and plus size which I use for tops, dresses etc. I have a mesh screen fixed to the wall with a sheet in front and hang the forms in front of that. For skirts and pants I hang at the waist then pin the skirt/pants to the mesh : Not one of my best but you get the idea.

there are quite a few good 2nd hand manequins that you can purchase. Either full body ones or half body ones for a cheap price Also with photoshop programs these days or even just using a white background or large white tablecloth on a large table makes it a bit more presentable if not using manequins.

If you want to photograph something flat use a board, propped up at say 45degrees or so against a table or chair etc. Peg a material backing sheet over this. Lay your item on it. The material will help stop it sliding down, and being at an angle you can take a photo closer to perpendicular to the item, this avoids that obvious angled floor shot.

You can use this same board and backing leaning close to vertical for hanger or body form shots too.

Then crop the photo so item takes up all the frame