So I totally took step by step pictures of the entire process of making this nursing dress when I made the fabric flower tutorial.... but it appears that I somehow deleted each and every one of them before getting Derek to take pictures of the dress on me. Sigh. So you'll have deal with very non-visual instructions on making yourself this dress. :(
1. Try on a tank and mark about 1" below a good empire waistline for you. Cut the bottom of tank off. (in retrospect I might have cut it so that the back was shorter than the front since you can see how it's longer in the back)
2. Cut a 4" strip from the top of the remaining bottom half of the tank. Fold in half. With right sides together pin and sew to the bottom of your Empire waist-ed tank top.
3. Measure around the fullest part of your hips if you're making this for nursing or the fullest part of your tummy if you're expecting (or if your hips are wider than your tummy measure that). Add 6-12" of ease (less if you're nursing, more if you're expecting and making this near the beginning of your pregnancy). Divide the measurement in half and add one inch.
So the formula looks like this Hip/tummy measurement + 6-12" / 2 + 1" = X or the width of the front and back skirt panels.
4. Now measure from the seam you made on your tank to the length you'd like the skirt to be. Add 2.5" for the seam and hem allowances.
Formula for length: Desired length + 2.5 = Y or length of skirt panel.
5. Cut 2 skirt panels X by Y. If you do full length like I did, you may want to taper the skirt out in a trapazoid fashion so that it's about 3-6" wider at the bottom than the top. I can't take too long of a stride in this dress because I didn't do that.
6. Sew skirt front and backs together at the side seams.
7. Make a tiny hem at the top of your skirt piece.
8. Hand wind a bobbin with elastic thread. Sew two lines of stitching around the top of the dress with the elastic thread in the bobbin and high tension on the top thread. (if you're making the dress nursing friendly, you may want to sew a couple extra lines of elastic in the front panel: especially if you're pregnant when you make the dress).
9. Pin the skirt to bodice seam right sides together with the waistband itself turned up and out of the way. (this is the hardest step without a picture. Basically, the skirt will be inside the front of the dress with the waistband turned out of the way. Your waistband will be sandwiched between the skirt and tank. I'm probably over explaining...)
Leave most of the skirt gathers at the front and back of the dress leaving the sides straight. If you want the dress to be nursing friendly, do NOT pin the front of the skirt to the bodice. The elastic thread should hold it up. If you're not concerned about nursing access then go ahead and pin the front down.
10. Try on the dress and adjust as necessary. Mark your hem placement and then turn up and sew your hem.
11. Embellish as desired. Enjoy your dress!