I altered the pattern to the muslin, then finally cut out the tweed.
I have this real silky thin polly thread that I used to sew a silk dress for a friend.
I have 4 cones of this stuff so I could overlock the fabric, so I didn't think new thread was needed. I forgot how strong this stuff was.
After I cut out the tweed, I basted tape along the armholes.
Next I cut out the interfacing for the garment. I bought some hair cloth, but it was right pricy, and I feel bad about using that on my first piece, so I decided to go with what the book suggests, a loose weave muslin. I just spent an hour ironing a piece I bought a few weeks ago. I soaked that thing with a spray bottle and steam working those wrinkles out after I washed it. I think I got all possibilities of shrinkage out.
I used my pattern which I cut with no seam allowance and it fit rather well.
I then cut away the fabric from the darts and did another steam pressing with both pieces sandwiched together.
I pinned the fabrics and traced with sharpie (I'm ghetto) on the muslin 2" apart with the grain. I then did a running stitch (the book refers to it as a tailor's stitch, I don't rightly see the difference, but I'm sure there is one) on the lines. I'm going to then go between them and make the spacing only 1" apart, like the book suggests.
I then need to catch stitch the edges of the muslin to keep them in place. Once I do that on the front and back (I'm going to also put a tiny bit of interfacing in the caps of the sleeves), I'll be ready to baste the jacket together for it's first fit. I'd say I'll be ready for that in a couple of days.