cutting plaid takes quite some time, but its worth it in the end, so its time well spend.
start with your pattern and mark points on sideseam on front and back
then when placing the pattern parts on the open fabric (with check never cut it folded), make sure top and hem and those markings match up with the same lines in the check. I matched it at the horizontal lines, but thought if the vertical lines didnt match up it wouldn’t be to bad.
be prepared that there is a lot of space in between pattern parts, even though my check is easy, because its the same form all side. draw on the parts, 2 times, mirroring each other, see how they fit with the check? place the pockets matching at least horizontal as well and cut all parts.
For the Jacket you do pretty much the same, make sure waist-marks are at the same horizontal lines, same as the front marking for the sleeve and the back and the elbow-markings. but the grain line is more important then the fabric match, so be sure its always cut in the right grain. You can’t have perfect matching lines at all seams. 😉
Questions, suggestions and wishes are most welcome! I hope this was helpful for you!
keep sewing and smiling