Add a full size bed, dresser with mirror, one or more chest, a cupboard, T.V stand and a wall unit. Apart from this some people love to have a coffee table with love seats in their bedroom.

A nice bedroom area, with a vanity and stool, in one area, and a canvas love seat, with a small glass coffee table, and TV, also a desk.

Get yourself a big desk 3 4K Gaming monitors and a powerful gaming PC. (if you have around $10,000 sitting around)

Put in shelves. There are many good options at Lowes or Home Depot that are easy to do and you always need shelves.

Hey! My bedroom is 12x20 and it's considerably too large for me, I'm only 16. How can I make the room not seem so big? It's a basement room, which is why it's so large by the way.

What furniture would you add?