I did a good bit on fitting adjustments, I already had my fabric picked up and I had to do an interlining. I have another project in the works where I was going to help some long-distance friends sew there first dress. One of them mentioned the fabric being semi-sheer. I suggested interlining and so now I'm here to explain what that is.
As you can see, my fabric is a somewhat sheer cotton lawn. I decided to use a light weight cotton batiste* for the interlining.

First I cut the pattern out of the interlining. Then I placed that on top of my fashion fabric (or shell, whatever you want to call it). I know I could have been a bit more frugal in fabric placement, but in this case I wanted the design to line up a certain way.

In most instances one would hand-stitch the two pieces together in the seam allowance. However, that takes forever (and machine stitching makes the two pieces to bunch and not line up properly). So I took a page out of Gertie's book and used fabric glue in the seam allowance instead. Works like a charm! Also, I put all my markings on the interlining before gluing and cutting.
*Please note that the color of your interlining can effect the appearance of your fashion fabric. I highly recommend taking the fashion fabric with you and trying it over several different colors. One can also use silk organza or really any other similar/lighter weight fabric. It really depends on what you want the end result to look and feel like. I personally can't stand polyester anymore as all it does is stick to you in hot Georgia summers. And my skin complains by breaking out. Not fun.