I found a tutorial somewhere on Google but it didn't have many pictures. I used most of their ideas because I'm not the creative type.
2- sheets of crackled rock plastic. I used the sheets that would cover up a fluorescent light. Home Depot had them for $5 each.
1- 2" x 8" board. Maybe 6 feet long.
1- light of some sort. You can use the inners of a lamp. I used one of those green outdoor lights that people stick in their gardens.
1- green light bulb
1- hot glue gun
1- wood burning tool
Step 1: Stencil
Cut out a stencil. Feel free to just kind of guess, you don't deserve to hoist the Crag so it doesn't need to be perfect. I went with a 22" base and 23" high. The slants were 6" and 4".
Step 2: Trace and Cut
Don't worry, I did all the trial and error for you. This process sucks. Don't use a razor blade. It takes for ever, looks terrible, and the plastic randomly cracks and you have to start over. I found a bad ass 1970's wood burning tool and that melted perfect lines into the plastic. I'm sure you could use a hot knife, as well. Scissors, razor blades, dremels, saws... pretty much anything that isn't a fiery piece of metal, won't work.
Step 3: Depth
Unless you're having a 2 dimensional party, you're gonna want to make your Cragg pop. I made mine 6 inches thick. Measure out the length of each of your slants, make them 6" thick, and get back to huffing that sweet, sweet plastic smoke.
Step 4: Assembly
Take some painters tape, and wrap that monster up. Make sure the rigged side is facing out.
Step 5: Glue
I found hot glue to be the easiest way to keep the sides together. It doesn't melt the plastic, but I would still be careful. The plastic is still quite see-through and you'll be able to see all of your mistakes.
Step 6: Base
The base is just a big rectangle. If you can't do that, you're better off just quitting now. Make your dimensions at least an inch larger on each side of the Crag. My Crag was 6" wide, so the base is 8" wide. A dremel cut a pretty nice groove into the base so the Crag had something to rest in. Paint that sucker black, and drill a hole for your light.
Step 7: Insides
The guts of your Crag will be the easiest part. I bought this piece of foam from the garden section of Joann fabrics. Carve it into two smaller Crags. They'll sandwich the light bulb so the light is dispersed. I hollowed the front facing one to give it a little more detail, and because I was at a friends house and wanted to make a mess. Not my house, not my problem.
Step 8: Attaching the Base and Logo
Load up that groove with some glue and slam your Crag into it. I printed the logo at CVS when no one was looking. I don't think Guts will care, but you can never be too careful. I don't need Mike O'Malley showing up at my door. Some clear polyurethane made for a nice clear coat to hold it in place, but if you need the $3 to buy some Taco Bell, you don't have to do it.
Step 9: Final
Boom, done. Only takes a day or two. This picture is of a friend of mine at our 90's party.