About a year ago I had a Thrift Store Prom Party to attend, and among
the many other jems I found was a studded belt with the Mistfits logo
as the buckle. It was cool, but I wanted to make my own buckle to
personalize it some more.
Here's my process....

Things used:
Epilog Laser Cutter
TechShop San Jose
SJSU Foundry
MDF
Dremel
Drill
Files
Resin Bonded Sand
alcohol/graphite
High temp tar sealant
Aluminum
wood and threaded rod
PC-7 epoxy

Step 1: Make the Pattern

Using one of the lasers at TechShop, some scrap MDF, and a .jpg that
I grabbed from Google Images, I cut and etched my pattern. Using a
Dremel, I accentuated some of the three dimensional details (made the
eye sockets deeper and rounded the edges). Modifying your pattern is
almost always easier than making changes once its cast in metal.

Step 2: Make the Sand Mold

First I made a simple wooden frame out of four pieces of wood. Place
the pattern in the center of the mold, you want an even boarder a few
inches all around to ensure a sturdy mold. Then pack the sand as even
as possible, and let it fully set up.
Once the sand has hardened, carefully take the this first half of the
mold out of the frame and flip it over so the bottom of the pattern is
exposed. Using a file, carve some registration marks for alignment.
Once again carefully put the first half of the mold back into the frame,
and then pack more sand to make part two of the mold. Once part two
finishes setting up take apart the frame and gently pull the two parts
away from one another. Carefully remove the pattern. With a mixture of
graphite and alcohol I coated the surface of the mold, and then burned
away the alocohol leaving a fine layer of graphite as a release. Using
a drill, make a couple holes for venting out any gases, and another
larger hole for the pour cup. For my mold I also drilled holes for my
threaded rod, which is used to securely hold both halves of the mold
together during the metal pouring process. Finally attach the pour cups,
directly above the larger hole, with the high temp tar sealant. Secure
the mold with the threaded rods, and it is ready for a metal pour!

Step 3: Metal Pour!

Get all your safety gear on and pour the molten metal into the pour
cup. Keep a steady hand and don't miss the hole ;)

Step 4: Clean Up

Destroy the mold! Retrieve your metal masterpiece! And de-gate (cut-off)
the unneccessary metal (and recycle it =).

Step 5: Turn It Into a Buckle

First I removed the Misfits buckle, and examined how it worked. There
were two holes where the buckle attaches to the belt, so I drilled
two holes into the crossbones. And there was a little hook in the back
to slide in and lock the belt. I drilled a small hole, big enough for the
wire, and then used PC-7 epoxy paste to adhere the wire to the aluminum
casting. Once the epoxy cures, affix the buckle to the belt, via the
two holes, and we're done.