Any tips from more advanced sewists would be much appreciated!
@Sibilantseamstress that is a lovely jacket. I love doing tailoring & that style of jacket particularly. I agree with you about an extra line of soft wadding (I use strips cut from old polyester jumpers) sewn along the sleeve head to make even a softer (no shoulder-pad) shoulder lne pop , as you say. Gives great definition - I have pretty broad & lean shoulders, so like broad shouldered stuff, and I find that technique (even in a dress) really adds a bit of smartness without any effort in wearing!
For setting in 2 or 3-piece sleeves, I have found that I run a machine ease stitching line for a lot more of the sleeve head (on the sleeve) than the pattern suggests.
And I run the seam exactly on the seam allowance line. Then when you pull it to gather up the sleeve piece a bit, as you sew over the actual seam, you're sewing exactly on the line of ease-stitching, and you don't then have to endlessly unpick the seam where you've sewn in unwanted gathers (unless gathers in the sleeve head are part of the garment design ...)
Then I ease, pin, ease, pin, ease, pin - pins in at 90 degrees to the seam/fabric edge. And lots - I might have a pin every eighth of an inch at least. If you've serged the edges of the bouclé you can be quite firm or strong with stretching the fabric. I start with a couple of pins to march the actual top of the sleeve, and the shoulder seam - you can sometimes play around with where the top of the sleeve sits, but it's important to get that line fixed first, as it affects the hang of a tailored sleeve. Then I pin at the depth of the underarm.
Then I ease and pin, ease, and pin, each side between those fixed points. That might be when I also clip the the jacket bodice in the sides of the arm hole seam/arm-scye - perpendicular to the fabric edge, and into about quarters of the seam allowance.
This stage can take aaages - but it's worth it for a really sharp finish. And very satisfying when you get it right! I put the arm-scye wadding in after I've set in the sleeve - makes the sleeve setting a bit easier.
I do the pinning with the sleeve inside the bodice, right sides together (obvs). Then I sew the first seam. Then I turn right side out and check I have no unwanted tiny puckers caught up in that seam - this is where the trick of sewing your ease stitch line of stitches exactly on the line of the eventual armhole seam really pays off!
If it's OK, I press out at the point, and really press out firmly, with an old cotton tea towel as my pressing cloth & a lot of steam.
Then once I'm happy with the set of the sleeve & it's hang, I do a second line of seaming to really strengthen the armhole seam. Then I grade the seam allowances, and if it's a fraying fabric, like a bouclé, I'd do a serger finish, or a softer zig-zag to finish the raw edge of the fabric.
But even with tailored stuff, then first thing I tend to do now, is serge all the raw edges, before I even start putting the garment together. Makes handling throughout easier.
Hope that helps!