I used this free pattern and tutorial over at Little Betty Designs. The pattern is size 1, but I altered it to fit a 6-month-old approximately.
The fabric is some super cute fabrics I got very cheap in the scrap bin at Spotlight. The mouse print is almost like a calico fabric, while the polka dots is a stretch cotton. It was my first time blatantly mixing patterns, something I have always wanted to attempt with all the wonderful inspiration around. The ruffles look crooked on the butt, they're not that crooked, but yes... they are not straight. I don't even know how I managed it but, who cares!