For the tutu I used:
a spool of tulle(I think it was 15ft or something, but I got 2 of them out of one spool). It's found in the ribbon section at Hobby Lobby.
I measured the onseie to see how wide the waist was and then cut and sewed the elastic accordingly (if I were to do it again, I'd probably shorten the width just a tad because it seemed to stretch as I added the tulle).
Then, I wrapped the tulle around a piece of cardboard that was 6.5" long. After I got the whole roll on it, I cut one end...leaving me with 13" stips.
I folded each strip in half (raw edges matching so that I didn't have to trim too much when I was finished) and made a simple slip knot.
For the onseie:
print out of a guitar
Following instructions for the wonder under, iron on a square that's just bigger than the guitar picture. Pin the print out on the fabric and cut it out. Iron guitar onto onesie (along with a little rectangle snippet for added detail).
For the hair bow:
extra guitar fabric
little metal hair clip
hot glue gunI cut a 18" long by 3"-ish strip of fabric, folded it in half and did a long basting stitch along the raw edges.
Repeat with a smaller section of tulle
Hot glue pieces together and add a button to hide the middle bunchiness :)