
This is the file cabinet I pimped out and featured at Casapinka. Many people have asked for a tutorial on it. Several people have emailed me to say they tried to make one but failed because it just looked awful. I, too, had a few snafus along the way and left it alone for a few days so I could let my foot heal from hauling off and kicking it.

First, you need to decide what you want on your file cabinet. I was inspired by Mary McDonald's chinoiserie which was photocopied wallpaper, and featured in Domino.
I took some decorative paper that I had lying around and enlarged it at Kinko's. It was more expensive than I thought so be aware of this. I don't think wrapping paper or anything too thin will work well - you need it to be at least as thick as photocopy paper because you're going to be agressive with the paste and don't want it to tear.

Supplies
Paper
Yardstick, or large self-healing mat (I really recommend the mat)
X-Acto blade
Decoupage medium (what I used - I'll refer to it as glue.) Spray adhesive might work as well.
Filing cabinet
Paintbrush - med to large
Instructions
There are two important steps and if you mess up either of them, you too will kick your file cabinet and end up on a vodka infusion.
The first important step is to properly measure your cabinet and cut the paper to fit. Using a yardstick and a self-healing mat with an X-acto knife is the easiest way I found to do this. Extra time here will save time later.

The second important step is to cut the paper for the sides into smaller pieces. For a tall cabinet like mine, cutting it horizontally into four quarters worked fine. Any larger and the glue seemed to dry before it was all brushed on. Major air bubbles ensued and it looked awful. For my first attempt I did the side as one large piece. I erroneously glued the metal rather than the paper and, well, it was ugly. Much swearing and a few vodkas later I figured out how to fix this, i.e. I cut it into smaller pieces and glued the paper not the metal.

On the back of your paper, brush your decoupage paste on as quickly as possible. DON'T miss any areas or there will be obvious air bubbles where it doesn't adhere to the metal. Don't be stingy with the paste - I was stingy initially and got inadequate coverage. Really paste the sucker. Note that the above image is the top of the paper (done later) which I used to demonstrate the thickness of the glue.
Take the paper and lightly place it on the metal. Start from the center and smooth the paper out in a small central area, as in a couple of inches,with your fingertips. Carefully move further and further from the center and have someone help you with this if possible. Be aggressive getting those air bubbles out, ALL OF THEM. As you're smoothing it down, if the paper is off center, just press in and slide it into place, but this is better done sooner rather than later.
If you go over the edges a bit you can X-Acto it off later, so don't worry if it's not exactly to size. This happened to me because my cabinet is dented and not perfectly straight.

After you finish the sides (I didn't do the top or back), remove the handles and latches from the front of the cabinet. Measure in to where your latch is because you will need to cut a hole in the paper to go around it.

Glue the front panels on using the same techinque as descibed for the sides, only this can be done without cutting the paper into smaller pieces.
I decided to paint my butterflies using latex craft paint. One thing I learned is that a nice paintbrush from an art store makes all the difference and really speeds things up! Here it is still wet.

After all of the paper is glued and painted, and the paint is dry, brush the decoupage paste on top of the paper, again taking care not to miss any spots. It takes about thirty minutes to dry.

When the paper is dry take a poke tool or needle and poke holes for the handles, then reattach them. I started out using an X-Acto to do this and it made messy holes - wouldn't recommend doing this.
After your are done, there may be some areas along the edges that didn't get glued down. You can easily spot treat these places with a small paintbrush dabbed in the glue.
VOILA!