Here is a not so short visual picture tutorial of how I do the necklines mainly for the lap over the shoulder Baby gowns. This is a modified Kwik Sew 3090 pattern. This particular one is the X-small/Newborn size and I left off the hand covers and I used ribbing for the neckline which I will show you.
First cut your pieces out. Here are mine all prepped for sewing. LABEL either (or both) the front/back pieces so you dont have to keep looking at the length to be reminded which is which.
Sew/Serge on the Ribbing to each neckline and sleeve.. stretch the RIBBING only and not the shirt with it. And stretch only slightly. I use one 17″ piece for ONE neckline and then one SLEEVE cuff.
IF you have any questions, feel free to post. :D