Make sure you have TONS of samples of your work.. Everything from single color to multi color (plus any kind of specialty effects you do (foil, distressed, vintage, etc).
Make it open and not cluttered. Make sure it's welcoming and well laid out.
A showroom is exactly what it says it is.. A room to show what you can do!! I'd suggest putting as much detail and time into it as you can. After all, it's all about image right?
