Unfortunately I'm writing way after the fact. Pretty much all there is to say is that I made croissants and they were darn tasty. You'll notice the shape is a little funny... I didn't cut them correctly so when they rolled up they weren't quite right. You're supposed to cut them like this:
...not into right triangles as I did. The basic procedure was to laminate the dough by filling with butter and folding, rolling, folding, etc. By the final fold the layers were so thin they wanted to rip, but it came out fine.
I'm not sure what recipe I used, but it might be this one:
The one thing I know for sure is that I used my sourdough starter. To use starter instead of commercial yeast I generally put in about a 1/4 c. of the starter and try to roughly add flour or water to make the consistency of the final dough right. It seemed to work well enough.