To make Skelly's coffin, you will need:

a skeleton (we named ours Skelly)
a large piece of cardboard (bigger than your skeleton)
straight edge
carpenter's square (optional)
razor knife, or some other way to score and cut your cardboard
hot glue gun
glue sticks
spray paint - we used 3 cans
bolt
extra decorations (optional), we used spiderweb and thumbtacks

Skelly was the most expensive part of our decoration. We got Skelly on sale for about $20. We used 3 cans of paint that were $1 each. We bought a cheap little glue gun and glue for about $5 and the spiderweb was $1. We had the razor knife, bolt, thumbtacks and giant cardboard. So altogether this cost us about $29.

Step 1: Drawing Out the Coffin

First, lay your cardboard on a flat surface. Draw a coffin shape onto the cardboard. Decide how deep you want your coffin to be. Ours was about 7 inches deep. From each corner, draw a line at a 90 degree angle from each line that makes the coffin. We used a carpenter's square but your straight edge held perpendicular to the coffin line will make a 90 degree angle as well. Repeat for every corner of your coffin. This will become the sides. After all of your depth lines have been drawn, draw a line connecting the ends. These lines will become your cut lines when we start cutting.

Step 2: Cutting Out the Coffin

Carefully cut around the outside lines, all the way around the coffin. Cut only one of the short ends on each of the flaps. Score the remaining short ends of the flaps.

When all the flaps have been scored or cut out, very carefully score the inside lines, the very first lines you drew to outline your coffin. Do not cut all the way through the cardboard. Scoring the lines will make them easier to bend into shape when we fold the cardboard into a coffin.

Step 3: Shaping the Coffin

Now it's time to turn flat cardboard into a 3d coffin. Carefully fold each flap, one at a time on the score line. The scored line will be on the outside (the back) off the coffin while the smooth folded edge will be on the inside of the coffin. Fold the flaps all the way around so that any adjustments can be made before you start securing the flaps together. Once all the flaps have been folded, carefully fold the scored ends of the flaps so that they will fit under the adjacent cardboard flap.

We initially started using duct tape to hold our coffin together but the tape doesn't hold the cardboard together very well and the paint flakes off so using hot glue works much better. Glue the overlapping parts of the flaps together all the way around the coffin. Be sure to hold the flaps in place while the glue dries to be sure it adheres well.

Step 4: Finish It Up

Once all the glue has dried and the coffin stands nicely on its own, it's time to paint. We painted ours with flat black spray paint. Paint the entire inside of the coffin and the outside of the flaps. The only part we did not paint was the back of the coffin. If the back will be seen, you may want to paint it as well. Let the paint dry well.

Step 5: Time to Decorate

Once all the paint has dried, you can hang up your skeleton. We poked a very small hole in the top of the coffin and poked Skelly's hanging loop through it. We used an old bolt to secure Skelly so that he wouldn't come out on his own. By looping the string around the threads of the bolt, the bolt held the skeleton securely upright inside the coffin. To add to the effect, we draped a few spiderwebs around him and secured them with thumbtacks. Voila! Now you have your very own creepy coffin!!!