Anna posted on Sunday about how to line the short-version bra. Her technique can be used on the long line version as well. I often line just my cups using a technique similar to Anna's, but I attach my lining prior to sewing my side seams, and sew both my lining and self fabric into my side seam. I love how many ways there are to finish a garment.
Your basted on elastic should pull the fabric 1-2" shorter.
Just a couple of steps left to go - adding the hooks and eyes, straps, and embellishments.
Who wants to sew a pair of panties after?