|The hardest part about sewing a pair of double welt pockets, and especially angled welt pockets, is making sure they're both in the proper position.
To help me ensure the welt pockets on a recent jacket project were symmetrical and set at the proper 30 degree angle, I constructed a template made of a clear plastic template sheet. These sheets can be found in the quilting section of sewing stores like Hancock and Joann.
I then took a Sharpie and drew a 1/4" high welt pocket window set at a 30 degree angle. Next, I used a rotary cutter and a small pair of scissors to cut out the window.
The welt pocket on my jacket crosses a princess seam line, so I drew the seam line in the proper position. You can see this seam line as a long, vertical line that crosses the window. To position my welt pocket, I simply match up the black line vertical line on the template with the princess seam line of the jacket.
I can also ensure the two welts are at the proper height by measuring their distance from the bottom hem. I have drawn horizontal lines running along the base of the template to help me select the proper distance.
This template is a quick, easy and inexpensive way to prevent welt pocket disasters. I recommend you construct one the next time you're sewing a pair of welt pockets.