Participating in some type of artisan exchange is a good way to practice your skills. In November 2014, I was part of the East Kingdom Artisanal Exchange. I was assigned Lady Rennewief van Grunewald, and given a variety of tidbits of information about her. The parts that struck me were that she had a later period German person, and her device was red and blue, with silver roses. The saltire line of division gave the opportunity for this pattern, by using red and blue colored thread (probably silk,) to secure each pleating gather of this honeycomb stitch. (really, I promise it was red and blue.) Little silver bead caps and clear seed beads created the roses. The fabric is a fairly thin linen.
Galla taught me pleatwork a decade ago, or so, and I still use that method. Rather than use a pleating machine (although they are really cool machines), I use a strip of plastic canvas about 3 inches wide and 18 inches long. I lay the plastic grid along the fabric a bit down from the top edge, and start marking. Move the strip of canvas as necessary, keeping it the same distance down from the raw edge. This had pretty small pleats, if I recall correctly, so I probably marked through the plastic canvas with disappearing fabric marker every other hole, so I had a neat grid. Other times I’ve skipped 2 or even 3 holes, for much deeper pleats. After pleating, add the apron strings and hem the sides & bottoms.
I do NOT pre-gather the pleats. I just connect two adjacent dots with a two back stitches, and then drop down to the next row and repeat. I’ve also been known to add a bead with each knot, and usually use 3 back stitches in that instance. Otherwise, the construction of the apron and how to make the pleating stitch is very like this nice pattern (with photos).
Pleatwork is known in more than just German areas, although the 16th C Germans really went to town with those styles. The extant paintings appear to show elaborate embroidery over the gathered pleats. There are extant 16th C modelbuchs, with designs that could easily be stitched across tightly gathered pleats. I didn’t actually consult a period source, just went with what would work heraldic-ly. However, this strip from the 1544 Modelbuch by Peter Quentel has some nice similarities.
The marking is the most time consuming part – stitching is a good time filler, and can be picked up and put down easily. Don’t be afraid to try this out.