Do you still remember Little Lady's Turquoise Dress? This bow is big and made for it. But you can use this tutorial for any dress or hair decoration... or what ever you desire.
The bow consists of the central part, bow itself and two ribbons.
You need tulle inside the bow to keep it in shape and fit. The tulle needs to be 1-2 cm more narrow than your bow's desired width. If you want the bow be 30 cm wide, the tulle needs to be 28 - 29 cm wide. You can easily ruffle 29 x 140 cm tulle on desired area. Make sure there is enough!
Sew the tulle from its middle part right in the middle of the bow. Make sure the tulle is as long as needed on both sides. If not; shorthen the longer side by using scissors.
Then sew it all up so that the tulle stays hidden inside. I you want the bow to be 12 cm high and 30 cm wide you need to cut a piece 26 x 62 cm (double to each direction plus 1 cm seam allowance for each edge).
This is how the bow's front side looks when the tulle is inside. Fasten the tulle before other sewing of the bow. These fastening stitches can be seen at front side but soon the central part of the bow will hide it.
Fold the back side of the bow like this to make it stay better in the desired form.
Pull the bow through the central part.
Tack the central part with hidden stiches to keep it there where it supposed to be.
Now there are the bow with its central part and ribbons.
Sew the bow ribbons together. And then tack to the back side of the bow.
How you want to fasten the bow?
I used small sew-on snaps. They are easy to locate on ready dress. You can use tiny hand stitches to avoid damaging the fabric. And the best of all; the bow can easily be removed if wanted to use the dress without it or if the dress needs to be washed up.