osewme

I did a web search on "how to set up a sewing room in space with slanted ceilings & got quite a few images. You have to just scroll down as the pictures with slanted ceilings are scattered throughout the images.
Like quiltingcandy stated above, I'm sure your room is finished by now & I'd love to see what you did with the space.

https://www.bing.com/images/search?q...IQFRML&first=1

tropit

My space also has slanted walls. For my stash storage, I took the triangular-shaped wall and hung curtains from it. I made them from inexpensive drop cloths that I bought at Harbor Freight, bought some clip-on rings and hung them from hooks on the wall. I put shelves behind the curtains and plastic bins to hold my fabrics. When I need to get my fabric, I just unhook the curtains and pull out a bin.

I'm sure you are done now and your place looks fabulous, but I would suggest that if you have the money, (or do a "free" search on CL,) you get some file cabinets to store the stuff that you have in the plastic drawers. I have a few of those drawers too and I find that they seem to attract dust, they're always falling apart and they feel so temporary. The cabinets will fit neatly under the slanted wall and look much nicer. They may even give you some desk top space to work on.

Peckish

First of all, before deciding how to organize, you need to think about your style and personality. What do I mean by that? Let me give you an example.
My husband is the kind of person who needs to see things. He can't see or find items if they're out of sight. His tools need to be visible. On the other hand, I can't focus if my workspace is cluttered. I need clean empty space, otherwise I find myself unmotivated and overwhelmed. So my tools and projects need a home that is in drawers or cupboards, out of sight.