The finished lining will be paired with the shell (right sides together) and the only seam to sew at this stage is the very long path that includes the left side, the collar and down again on the right side. Don’t close up the the bottom hem yet. That opening will be your necessary access point if you want to finish the sleeve cuff linings correctly.
I like to make this tremendously long seam in two trips. I start at the centre of the collar and go out and down the buttonhole side of the front. Then, I return to where I started, overlap my first stitches a bit at collar back, and go the opposite way along and down the button side of the front to bottom. If there is any excess bulk, it will distribute evenly and won’t distort the critical pivots at collar points.
Trim your seams and clip where needed to turn and press. Leave hem open.