Leaving your windows uncovered is a great way to make a room appear more spacious. When you cover your windows with heavy window treatments you are creating more distractions and clutter while also blocking useful light.
This is a before and after shot of a small space in an apartment. Notice how adding a fireplace with a mirror makes the room appear much larger than it is. Mirrors are your best friend in a small space.
Add storage in every place possible. Here storage is above the bed to keep it off the ground. Keeping the floor open is a great way to open up the room.
This is another before and after image of a small living room. Look how painting the room white adds so much more room!!! Also another key is to keep your furniture low in profile. The lower the better. Adding height only accentuates how small your ceilings are. By bringing the furniture closer to the ground your ceilings appear higher.
Bed by night, sofa by day. Multi-use furniture makes sense in a studio apartment.
If you have a small division create openings to let light in and make the room feel more open.
There are many other things you can do to open up a space but remember the basics. Light colors and small scale furniture.