I mention briefly in the intro to the pattern instructions about adding a lining and here’s how to do it.  You can use any thin material; I like cotton because of its breathability.  If you did a mock-up of your dress (and you should), you can even use the same pieces, providing you did not have to alter them beyond use.

I usually do the neck and sleeves after the bodice is built, as they are a bit easier before the skirt and zipper are added, but you can also put the whole thing in at the end.

To start, check that your lining pieces have the same seam allowance as your dress pieces.  Sew the bodice front and backs together shoulder and side seams, and attach the sleeves but do not hem them.

How your lining attaches depends on how your neck edge is being finished off.

Finishing the edge with a satin stitch?

(You can do this step now, or at the end)  Press over the seam allowance at the neck edge of your lining, but press over a 1/4″ in from the neckline (so if you have 1/2″ of seam allowance at the neck, you’ll press over 3/4″).  Pin the lining to the inside of the dress, so the lining sits 1/4″ in from the edge.  Slip-stitch the lining to the dress.  You can stitch it to the fabric if it is textured, like velvet.  Otherwise, carefully attach it to the satin stitching (see picture below).  Stop stitching 1.5″ away from the center-back seam line.

(You can do this step now, or at the end)  Follow the instructions above for finishing with a satin stitch, except that you can press the lining seam allowance right on the neck line, rather than 1/4″ in.  When pinned and stitched, the lining should line up with the neck edge line instead of being 1/4″ below, as directed above.  I don’t have a picture of this, but it’s fairly similar to the instructions above.

Pin the lining to the dress at the neck edge with right sides together.  Stitch along the neckline.  Clip seam allowance and turn lining towards the inside.  Press the seam.  If desired, stitch 1/4″ away from the edge (see picture below).  Stop stitching 1.5″ away from the center-back seam line.  For the dress below, I topstitched a small facing to the neck edge of my lining first, so the white wouldn’t peak out the top.

Follow the steps above for finishing with a satin stitch or with a collar, whichever is applicable.  If you don’t have a collar, use the satin-stitching method, so the facing stays away from the edge.  See step 5 (center back) before stitching all the way to the zipper.

If your sleeves aren’t sewn into their respective bodices, do that now.  Hem your dress sleeves (but not the linings).  Press the hem of the sleeve linings up 1/2″ shorter than the original hem, and slip-stitch the lining down 1/2″ away from the hem edge.

4.  You’ll now continue on with the regular instructions, making your skirt, sewing the dropped waist seam, putting in your zipper, and everything else until the dress is finished.  I would even sew on any cape velcro you have to add to the dress now.  Make sure your lining stays out of the zipper and dropped-waist seam.

Press the seam allowance up along the bottom edge of your bodice lining.  Pin the folded edge right along the dropped waist stitching line (you can see the stitching line in the picture, where I’ve pulled the lining up a bit).  To ensure your lining isn’t too tight up and down, have your dancer try it on quick, or put it on a dress form.  If your dress fabric is loose and bubbling, the lining might be too short and tight.  Re-press the lining 1/4″ down to loosen it up.  Slip-stitch the lining to the inside of the dropped waist seam, stopping your stitching 1.5″ away from the center back.

Press over the center-back seam allowance 1/4″ away from the seam line.  Pin the folded edge to the inside of the zipper, 1/4″ away from the edge.  If you stitched the zipper on 1/4″ away from the edge, you can use the stitching as a handy guide.  Slip-stitch the lining to the inside of the zipper, and finish off the small gaps in stitching at the back of the neck and dropped-waist seam.

Your dress is now beautifully lined.  Linings not only catch sweat, but they also make the dress more comfortable.  Enjoy!