Great use for hankies, Peter Pan Collar tanks! Tutorial

I'm proud to say I came up with this one on my own (I think).
I collect cute vintage hankies and have way too many, even with selling some in my Etsy store.  As a fun way to dress up summery tanks and tees, I've decided to make Peter Pan collars (that means the classic cutesy rounded-edge, vintage-ey shape) out of decorated hankies and put them on plain tees and tanks!
To do this, you'll need a tank, a hankie, and some white cotton for the underside of the collar.  Here's what I'm starting with:

I'm going to show you how to do two styles of collar--one that wraps around to the back and one that's just a fake collar, only in front.  You may not have enough hankie fabric to do the full collar; I ran into this problem with one of my hankies, so it's only on the front!
So here's what I did.

• Fold the tank in half and make a pattern that follows the curve of its neckline.

• Using the arc, create the shape of the collar--just eyeball it!

• Cut out around the collar adding a 1/2-5/8" seam allowance, whatever you prefer.  This is your pattern piece, which you'll use to cut out from the hankie and the white cotton.

• If you have enough hankie to do a full collar, do the same thing but trace around to the back of the tank, too:

 It's okay if your lining and hankie fabrics don't match up perfectly, or if you don't have 100% enough fabric... the uneven places will get lost in the seam allowance.

• Turn the pieces right sides together and sew *along the curved edge only*.

• You're going to flip and press, but first clip along the curve in the seam allowance so you don't have bulk along the edge.

• Flip and press.

• Press under 1/2" through both layers and clip along that curve, too.

• Find the center of your tank and pin the collar down, using your 1/2" fold as the guide to fit the edge of the tank directly into.  Sew (on the inside of the tank) along the curve.

• If you're doing the partial collar, turn under 1/4"-1/2" at the top and finish the seam on the inside.  Then hand-sew the fold down.

 That's it!