(All of the images on the right can be enlarged by clicking on them.)
The other side of the fabric. As you can see, even with the black thread the stitches don't show much at all.
This next stitch is a running back stitch. It does exactly what the name implies: it combines a running stitch with a back stitch. It isn't as strong as a back stitch, but it's a lot faster to do.
To make it, for every back stitch you make, put the needle through the fabric twice like a running stitch, then back stitch, and repeat.
The next stitch combines the last two: the flat fell. Put the two pieces of fabric together, offsetting one by 1/8". Stitch them together: in this example I used a running back stitch, but for the Regency shirt I used a regular back stitch so it would be stronger. (This is also what the above running back stitch looks like when it's finished.)
Fold the overlapped edge down, and then fold again along the stitch line so that the fabric now likes flat. Using the fell stitch, sew along the open hem to hold it down. This is what it will look like from the back.
You can load a couple of these stitches on the thread before pulling them tight, which rolls the hem up and finishes it.