To add a ruffle bottom to a onesie, you CAN just take pre-ruffled fabric/lace from the fabric store and so it on, which I've done. BUT if you want that little bottom to look fluffy, and pheasant-like, then here is another alternative!
-( 1 yard-ish) nylon chiffon or tule, or other non-fraying translucent material
1.cut 3 strips of the chiffon the lengths you want the ruffles to end up. make the strips about 3/4 to 1 inch wide.
2. next, cut out approx 9-12 circles per strip (depending on how long your strips are. mine were 5 1/2 in. long and I used 9 circles that were 2-3 in. in diameter).
3. Then you take the circles and sew them on. I am going to demonstrate this step-by-step so you can see how to scrunch the circles up. (first, fold the circle in half.)
do you just love my chipped gray nail polish?? J/K!!
(then fold it in half again)
4.Then you put the strip under the foot with one of the scrunched circles. Bring the needle down and sew a few stitches (and backstitch) over the point of the circle. To put the next one in, keep the needle down in the fabric, but lift up the foot. Insert another scrunched circle with the tip of the circle (the part in the photo above that is in between my thumb and index finger) about 1/2 in apart from the tip of the other one. Sew some more. Continue to do this until you have circles covering all the strips.
5.Last: place the strips on the bum of the onesie and sew it down (over the same line that you sewed the first time) Then FLUFF!!! and put it on your sweet baby girl! If you want to know how I did the front, here is a peek:
I cut out an oval of felt, and then sewed the circle onto it the same way I did on the strips. Then I sewed on 2 more pinked-edged felt ovals on top of that! easy peasy!
oh how I love this girl. And she is only 6 months so she still wears all the stuff I make for her without a fuss:) baby legwarmer tutorial here.