My fabric was a lightweight cotton jersey and I found it was a bit too flimsy for the collar piece, it just didn't drape well at all. So I cut two collar pieces, stitched them right sides together along the outer edge and then treated them as a single piece and continued making the top.
This is such an easy top to make, the fit is good, I didn't make any alterations from my usual size 38. I managed to get the stripes matching up on the front, but it's a different story at the back! I don't think it matters too much though, especially for a $1, 2 hour top (probably 1 hour for normal sewers!).
Here I am wearing it (of course it would have been better if I had pulled it on over my bust properly and not worn underwear that shows with the camera flash, but we're all friends here and hopefully you get the general idea! You just don't notice these things on the camera display!).