One way to drastically transform the immediate look of a room is to change the floors. While that might seem counterintuitive, as the floor is not at eye-level, it can still have a profound effect on the appearance of a room. For example, if you've decide to rip out the old carpet in the room and give the wood floor beneath it a shiny stain, your room will look instantly newer, brighter and more chic. However, for that project and many others, you'll first have to sand the floorboards. Most people rent floor sanders that you push like a lawnmower, but if you have a small floor or surface area to sand, you can do it by hand with an electric sander.
Check the floorboards for nails that are sticking up. Drive them down with a hammer. Hammer down any loose floorboards. Vacuum the floors to get rid of debris.
Attach a piece of 40-grit sandpaper to the bottom of your electric sander. Run the sander from left to right across all the floorboards, removing all the old finish. Take your time, moving the sander back and forth, stripping the wood completely.
Attach a piece of 80-grit sanding paper to the bottom of the sander and repeat this process. Repeat once more with a sheet of 100-grit sandpaper.
Vacuum up all the dust from sanding.
Since you're just using an electric sander, you may need to use multiple sheets of 40-, 80- and 100-grit sandpaper to cover the floor uniformly.