To do a simple hem: fold the fabric up 1 inch, and then fold the raw edge under about 1/4 inch. To keep the fabric from stretching, I put a strip of tracing paper or tissue paper under the fabric as I sew it. Then I just rip it off when finished! Any little bits of paper that are left usually wash off in the first wash. You can also try a walking foot on your sewing machine. Other variations include using a double needle to make a more professional looking hem.
I call this the Onesie Finish, because, well, that’s how a lot of onesies are finished! Simply serge along the edge without stretching the fabric. Because the pattern calls for hemming, you need to either serge off at 1 inch, or cut the hem up to about 1/2 an inch and then serge. This may not work as well on a lighter weight fabric. The lighter it is, the more it will stretch when you serge, even if you don’t try to. I notice that even if it stretches a little bit- like you can see in the picture- when it’s washed, the fabric will relax back into a nice shape. You can use this hem for boys or girls stuff.
Faux Lettuce Edge:
Faux Lettuce Edging is a nice variation of the Onesie Finish. Simply serge the fabric, but stretch it out as it goes through the serger by pulling back on the fabric. There is a special setting and foot for a real lettuce edge, but I find this to suit just fine. Because the pattern calls for hemming, you need to either serge off at 1 inch, or cut the hem up to about 1/2 an inch and then serge.
Chrissy Leiberan-Titus writes for Muse of the Morning.com