This set is for a little girl who is 7 months old, so the pants will not actually stick out from under the top so much... just wanted you to see them!
Simply take a pants pattern (no Brits... I do not mean knickers, I mean pants as every South African understands the word - trousers) for a little one, remove about 7cm from the bottom of the pattern piece, and then add a 7cm ruffle.
It is REALLY easy to make a ruffle using this method:
Turn your stitch length to the longest (basting stitch)
Change your tension to the lowest tension on the top thread - so that the top thread is as slack as possible
Using a straight stitch, start stitching
Gently hold the top thread between thumb and index finger just past the reel of thread.
If your fabric is not gathering enough, apply more pressure to the thread - just be careful not to snap the thread by holding it too tight. Best to practice on a scrap.
Gathering too much? Apply less.
Once you have it figured out, move to your actual project & keep the pressure on the thread even the whole way across. The result? Evenly spaced ruffles and no trying to pull bobbin threads after stitching two lines of basting stitch (as you are always told to do this).
Happy ruffling :)