I've been using a home studio for my ad music work for a long time. Though years ago it was all-analog, and in a different house with a large console and tape machines, I'm now "in the box" for competitive reasons (deadlines are much shorter now). The studio is a long, rectangular room in my basement. It's 33' x 17', though it narrows slightly near the workstation. The room is absolutely nothing special but I tried to make it nice looking for when clients come over. I call it Studio Craptastic for obvious reasons!
I'm attaching a couple of pics - maybe they'll help with some ideas. And it's always fun to check out other studios.
My brother and I built the workstation desk and the keyboard side desk from scratch in the '90s and they're still going strong and look new. We even welded the legs. It took a few days to build but turned out well. The corners are mitered, and the work surfaces are double-ply with maple edging. We glued formica to the tops, so it's easy to keep clean.
I also bought a couple of flat-pack racks from Argosy that were reasonably priced, and they look nice.
Ikea makes some sturdy shelf units and cabinets that are intended for office use. The series is called 'Galant'. They're significantly more rugged than most of Ikea's stuff. As needs grew, I assembled some of these shelves and cabinets for in-room storage. They work fine and are very solid (I also have a separate storage room). The shelves each handle 66 pounds, and the black ones are real stained ash veneer, so they look pretty good, all things considered, even up close.
I had Real Traps help me with placement of the acoustic materials and bass traps they make; again, not terribly expensive. They work extremely well, the room sounds great.
Over the years I added some artwork and some nicknacks to give the place a little personality.
Here's the workstation area with the home-made furniture and some of the Ikea stuff:
The recording area in the rear of the room with Ikea Galant drawer unit and shelves, and another Argosy rack. Granted, it's nothing special but for me it's a nice place to work.