This is another Star Wars corky, voted by other users in my Yoda Instructable. I tried to make this as accurate as possible, but the fur I used wasn't ideal for the job, so it didn't turn out as well as I expected. Anyways, here's how I did it.

Step 1: Supplies

Supplies:

Chamagne cork
Extra piece of cork
Small black pins
Artificial brown fur
Aluminium tape
Light brown fabric
Needle nosed pliers
Craft knife
Brown and black permanent markers
UHU glue
Scissors
Chisel-tip soldering iron

Step 2: Modifying the Cork

Unlike most other corkies, Chewbacca, being a Wookiee, has animalistic features. It would have been very difficult to achieve the proper look with a cork with straight sides, so I carved away some of one side of the cork.

Also, glue/pin an extra disc of cork (from another champagne cork) to the bottom of the cork. This is to make the cork taller, as Wookiees are taller than most humans.

Step 3: Fur

The fur was the tricky part. Ideally, you would want a few different shades of brown, ranging from dark brown to dark blonde. The face should really be blonde, but all I had was this brown fur, so I had to work with that.

Start off by glueing a strip of fur across the top. Make sure that the direction of the fur is away from the face, as shown above. Add more strips of fur to the sides of the head until the entire top is covered in fur. Next, glue a thicker strip of fur and glue it around the body. This step could also have been done first, it doesn't really make a difference. Glue a further strip to the bottom of the face, with the fur direction towards the bottom. Cover any gaps with fur to make the cork completely covered.

Step 4: Face

For the eyes, I used a couple of black plastic pins. Shorten the pins to about a centimeter so that they won't poke out the back of the cork. Then, use a black permanent marker to give them a shiny black color.
Use a third pin for the nose. Instead of leaving it as it is, however, shave away a bit of the sides to give it a triangular shape, to make it look like a nose. If you can, color the pin brown instead of black.

At first I was going to just leave the mouth out completely, but then I realized that my cork resembled more of a dog than a Wookiee. The solution for the mouth didn't turn out to be as complicated as I had thought it would be. Use a chisel-tip soldering iron to burn away a section of the fur of the face, as shown above. You might want to practice this with some scraps of fur glued to another cork, just to make sure that it works and that you don't end up ruining your cork (this is why it's important to use artificial fur, not real fur).
To make the teeth, cut out two small bits of paper as shown above, and glue them to the top and bottom of the mouth. Cover them up a little with some more fur.

Step 5: Utility Belt and Pouch

Finally, the belt. Cut a narrow strip of light brown fabric, long enough to reach around the cork diagonally. Then, stick small squares of aluminium tape along the length of the strip and draw a line across all of the squares with a brown permanent marker (see last image). To make the pouch, cut out a small rectangle of the same fabric and glue it as shown above. Attach it to the utility belt.