Put curtains up it makes the place feel more homey. Also hang art work or shelves with pictures on them. You can also put up wall mounted candle holders. Then pick out a nice area rug that brings out the colors in your furniture. Another idea is to pick a nice neutral color for the walls and paint them.
Three things: lighting, color, and seating. Use multiple small lighting sources and design contrast between brightly-lit areas and darker, moodier areas. Paint at least one wall if you can, but use color as much as possible for psychological effect. And use seating to "instruct" people how to relate to each other. Get creative, adjust as you go, experiment, learn.
Go to the library and research decorating ideas for small spaces. Avoid clutter and collections. Create a single focal point in each room. Look for furniture that doubles for storage (an ottoman, upholstered seating cubes). Plan kitchen storage carefully and only keep or purchase what you have space for. In a smaller space, less is more.
When decortating an apartment, house, or anything that you will spending alot of time in, its best to do something that intrests you. You have to look at it everyday.
some good ideas for decorating an apartment are painting,interior decoration,creating decorative warmth lamp,wallets,filling more heavier and expensive furnitures,Using bright colors and light walls to the apartment. Wrap-around sofa in a dark color,contrast dark furniture colors with light, open walls and colorful prints.