I got back to work on the skirt today. I have a lot of pictures of the progress of the skirt, and I intend to eventually compile a how-to for this pattern, New Look 6343.
In the meantime, here are some pictures to describe how I press open the side seam of this skirt. I use "Dritz Ezy-Hem" plates, which are metal and thus help to suck the heat out of the fabric. I also use a "ShopSmith" 2" x 48" aluminum ruler, which is also metal and also rather heavy.
I pull the skirt over the ironing board with side seam centered, hem first. I pull it on so far that the waist is inside the tip of the ironing board:
I press open the top half of the side seam, place two hemming plates over the opened seam, and place the iron on top to hold them down until the pressed seam (and the plates) cool:
I pull the skirt waist off the ironing board until the lower part of the side seam is straight. I press that seam open and place a shopsmith ruler over the opened seam allowances until they cool.
Here is a close-up of the pressed side seam.
Here's the other side seam, ready to be pressed. I don't know why I didn't notice before that the length of the skirt would fit on the ironing board.
Here is the pressed side seam, cooling off.