Here we are at day 3! Time to finish our dresses (if you haven't done so already)! By now, we have our bodices and skirts sewn and attached - everywhere except center back for lined-bodice only and all but center back and side seams for fully-lined dresses.
View of [altered] bodice back
If you are using trim(s), be sure to attach it to the dress before applying the zipper. I pressed my outer fabric empire seam down (toward the skirt) and overcasted. On the outside, I applied a grosgrain ribbon right along the seam line. This flattens and hides the appearance of the seam. Sew ribbons slowly and always from the same direction to keep the grain vertical.
Now, I recommend overcasting/serging your center back seams. For those with full lining, since your two layers are attached at the neckline, you can separate them and sew one long seam. Overcasting your center back seam in advance will prevent any awkward navigating around the bottom of the zipper. It will also give a more polished interior look to the partially lined dresses.
To continue with the zipper, use the instructions from my invisible zipper post. (I used them as a reference too, as this is only my second one ;) ) If you aren't doing a fully lined dress, you can immediately sew your zipper to each side after basting, omiting the steps with lining. Now that your zipper is attached, sew your center back seam, and side seams (if applicable) and press open your seam allowances.
Small slit cut in hem at crease
Time for the final section - the hem! The first time I tried to hem a dress, I wasn't entirely pleased with the result. Since no dress pattern has a bottom edge with a perfect 45 degree angle, you'll be folding a slightly wider bit of material into a smaller one. This causes a few minor creases. To alleviate the bulk of these creases, it is best recommended to cut a small slit at every bunch, until the hem lays flat (make sure your hem is pressed evenly before any cutting!).
Of course, now you have, in my opinion, unsightly notches in your otherwise smooth, even fabric. Enter hem lace! I'd seen this countless times in the fabric store and always thought it would be a nice touch but, frankly, unnecessary and a waste of money. I couldn't think what it would be for. Now, I'll be using it in every sundress I make to cover up those notches! Attach the bottom of the lace to the fabric before hemming, matching the top edges. Close the hem, sewing through the top edge of the lace and both layers of fabric.
Finished hem at side seam
Congratulations! Your sundress is now finished! I hope this has been fun and helpful - I'd really love to see pictures! Be sure to post links to your photos and/or blog posts in the comments section below. After all, a sew along is about group participation and mutual accomplishment.