There are infinite possibilities of lighting accents that can be applied to small spaces without taking up volatile floor space. In the bedroom sconces can be a bedside accent proving very useful if you enjoy reading before bed. The sconces pictured below are very fitting for an apartment because you don't need an electrician to install them, they plug into the wall just like a regular lamp. Sconces with plugs have been popping up all over the place because people no longer have the time or money to install a sconce, they can be found at trendy places like Crate and Barrel, Z-Gallerie and I.O. Metro. If you're looking for a cheaper alternative Target has started to carry a few as well.
Lighting can also be a very affective medium when you're trying to set a mood in your space. In a sitting area lamps can be used in the evening to create a subtle glow without the expense of dimmers. I also like the idea of adding candle sconces next to a work of art so the natural candle line can beam across it allowing the eye to see the piece in a "new light."
Source: The Designer Insider; Above are some very fun varieties of candle sconces. If you're buying on a budget I recommend looking at Hobby Lobby, they have a great selection of home decor for great prices, especially candle accessories. Hobby Lobby also has great 50% off sales that are updated weekly. There is always a section in their news letters that can be found online at hobbylobby.com; giving a detailed list of the sale items. It has become one of my favorite places for purchasing home goods.
Source: Grahamandgreen.co.uk; When decorating a small space I also recommend using lamps with clear bases. They allow light to escape through them and they look like they are floating, allowing you to reap the benefits of lighting without the cluster effect of a large solid lamp base.
Source: decorpad.com; If you are searching for overhead lighting and don't won't the hassle of installing a fixture an ark lamp is a great alternative. Ark lamps are very versatile, they can be used as dinning room lighting or next to a small sectional as pictured above.