Alaina Zulli, a dressmaker and costume historian who specializes in historical sewing techniques, has put up a three-part tutorial for making a corset at CRAFT:

Part 1
Part 2
Part 3

I’m sorry the series wasn’t published a month or so ago, when I was making this costume for Shadaughter; I could have used a few pointers.

Fortunately, if you’re interested in making a corset of your own, it’s actually not as difficult as you might expect. If you can sew a straight seam, you can make a corset. “Historical” patterns seem to be very popular right now, so many major pattern companies have easy-to-follow patterns and instructions for period undergarments. I used Simplicity #5726 for the corset and chemise, and except for the WTF-ness of the instructions for inserting 24 steel bones of various lengths consisting of a single, airy, “Be sure to insert the bones in the correct sleeves,”* it was actually quite straighforward.

Corset hardware is a bit specialized and doesn’t seem to be readily available in the fabric stores I frequent, but I was able to find everything I needed online. I ordered from corsetmaking.com and Lost Coast, and both companies were great to work with.

Custom corsets can be extremely expensive, but with a little patience you can create your own for a fraction of the cost.

*I’m going to pray that they never start writing instructions for Ikea, since I assume they’d be, “Open box. Assemble furniture.”