Don't try to make it look bigger. Make it cozy instead. This can be done by using a lot of coordinated fabric to cover walls windows, bedding, everything coordinate your entire house and just make it pop with color or pattern, whichever you are comfortable with.Fabric can be hung on pole rods on walls to extend window walls and so on.

Choose your color scheme and build your patterns from them.

Get rid of your little junk and collections. This can be hard, but

clean it out! Simplify as much as possible. Have Fun!