Big or small the most important thing is to make it your own; express yourself with use of colors, textures and accents. When I am working on a room I always begin with my color's; once you know that you can plan on the style and size of the furniture needed. Decorating on a budget is a great way to show what you can do.
Paint can work wonders; and you don't have to stick with one color but you do need to keep within the same "tones".
Great places to look for decor; Big Lots, Yard Sales, Estate Sales, "your friends", and never look at something for what it is but for what it can be.
Here is an idea for a great "feature wall"; go to yard sales and pick up inexpensive picture frames (don't worry) about the color just the styles. Various sizes and styles; and a can of spray paint will unify them. Now create a layout on the floor and once you find the perfect one...place them one by one on the wall! Art!!!!