How do you get plaid to line up at patch pockets without going crazy?

The pocket drifting you’re seeing is almost always down to tension and fabric movement, particularly when working with a dense wool like that. Instead of just pinning and sewing immediatly, you relly need to treat the pockets like appliqué until the final seam. Try using basting stitches—long, loose ones—to secure the entire pocket perimeter onto the shirt first. This locks the placement down without damaging the final stitches. Once the pockets are completley stabilized, then you can machine stitch over the basting line, and you should find that wandering disappears. Working from the back is good, but the key is ensuring the pocket itself is rigidly fixed before the sewing starts.

When it comes to matching large checks, cutting on the same repeat is correct, but the wool’s bulk will naturally try to shift the alignment during handling. Since this is a heavy woven fabric, you need to clip the pockets into place rather than just relying on pins. Use tailor’s clips to hold the pocket precisely where it needs to be, which gives you a much firmer grip than pins do. For the alignment itself, try measuring the repeat pattern before cutting the pocket pieces to confirm where the stripes will land, then use a chalk line to transfer those precise alignment points onto the shirt fabric before you start tacking the pocket on. Regarding your machine problems, if it's chewing through needles on a beefy wool, the needle type is the likely culprit, not necessarily your technique. Standard universal needles just don’t have the strength or point geometry needed to penetrate thick, resilient fibers like a heavy wool. You need a proper denim or utility needle for that weight of fabric. Also, double-check your presser foot pressure; if it's set too high, it can drag the fabric and cause that initial pocket shift while simultaneously straining the machine. Lower the pressure slightly while sewing the hems and pockets to give the machine more breathing room. It’s alot of fiddly work when you’re dealing with heavy pattern matching, but those pockets will hold if you commit to the basting technique first. Good luck getting those tartan lines settled.

For the pocket drift, I had the same thing happen on a flannel shirt last winter and the fix for me was a washable glue stick. Dab it on the pocket edges, press with a hot iron to tack it down, and it just does not creep while you stitch. Peeled right off after, no residue. Might be worth trying before you unpick a fourth time. On the needles, my old machine kept snapping them on wool coats too and it turned out the needle was bending slightly and hitting the plate, so check yours is straight before blaming the fabric.

I guess I'm bad at getting those big stripes to line up right even before I sew anything. I tried using a big ruler to trace the pattern onto the shirt fabric first, but with this thick wool, it just seems to bubble up and move when I press it down. It’s hard to keep everythign flat and perfect. The person who talked about clipping the pockets seemed to have it handled well, but I just want to make sure the stripes match from the corner all the way down. When you are tracing the pattern onto the shirt fabric first, what kind of chalk do you use that doesn't smudge or move when the wool is so stiff?

I totally get the fussiness with the alignment, though I’ve been running into this issue with a diffrent kind of fabric lately. I was trying to make a large drapery curtain and the sheer scale of the pattern match was just brutal. It was far harder than the pockets because you’re dealing with huge, flowing areas, not just small stiff pieces. I end up getting the sections aligned perfectly on the cutting table, but when I try to hang them up or even just pin them for a test, they just seem to want to shift and slump. I feel like I need some sort of stabilizer beneath the fabric before I even try attaching it, but I’m not sure what kind. It makes me wonder if the heavy wool is just resisting being pressed into place in a way that regular fabric wouldn't, or if there’s something more to the fabric itself.

Quick update — I tried using the glue stick trick for the pockets and it kept them perfectly in place while stitching. That solved the drifting issue, wich was a big relief. However, the horizontal stripes still seem to be shifting slightly when I press the pattern onto the wool. How do people keep that thick material totally flat when tracing?