Here's a quick DIY fix to get your deposit back when you move out of wood floored rental property or if you've invited everyone and their cousins over for a big party and realized that your wood floors look like ...well, you know. I came up with and have used this technique upon moving out of our last two rentals with great success. With this low cost, quick and genuine method, there'll be no need to completely refinish a gently worn wood floor by sanding and applying several coats finish just to get your money back (which would probably cost as much or more than your damage deposit in the first place).
All you need for this project is a small can of clear polyurethane (I prefer semi-gloss, but gloss could be appropriate too), a pair or two of nitrile gloves (I keep them stocked in the kitchen for handling meats), some clean smooth rags (that you will throw away), and your favorite mop (with a clean head). keeping a can of mineral spirits on hand is a good idea but hopefully you won't have to use it. A quart of polyurethane should be more than enough to do a two bedroom apartment with wood floors throughout.
With the apartment empty, thoroughly sweep the entire floor and then mop with the hottest plain water that is practical. The hot water will evaporate faster and keep the wood dry. Start at the furthest point from the exit and apply the polyurethane to the perfectly clean floor with a clean rag. Be sure to wear the nitrile gloves to avoid having to clean up with mineral spirits or other chemicals.
Work your way from the furthest points toward the door making sure to stay caught up by doing all the bedrooms and other out of the way places before sealing them off with wet finish in the hall. If your rag starts getting worn out wrap a new rag around the outside and continue. Wipe on the finish in a pattern that you can keep track of and can avoid rubbing up against edges that have started to dry and become tacky.
It is a really good idea to go all the way to the edges of the room to avoid a big shiny spot in the middle of the floor or even a dull border all the way around the room. When you get to the door work your self right out the door, close it and turn in your key the next day (so your landlords don't walk through the same day and step in wet finish). Your landlords will be duely impressed with how well you've maintained the gleaming floors and maybe not notice the toothpaste you used to patch those holes in the walls.
Now, before anyone jumps down my throat for proposing shoddy and unscrupulous tactics, I'd like to clarify the difference between true refinishing and my method. True refinishing of a floor is a long and tedious process which results in a pristine and durable finish that should last 5-8 years before needing to be redone. My method produces a far less durable finish overall but does fill in fine scratches in the finish and restores the original "gleam" that was probably advertised when you moved in. With either method that original gleam seldom lasts long anyway and, when done properly, my method does no harm to the floor or the overall functionality of the finish, it merely blends away some of the wear and tear you've already put on it. This will not work on badly worn or damaged floors but this method can help you keep knitt-picky landlords or gossipy guests happy with the state of your abode.