Once I stop sharing old projects I'll start taking before and after pictures. This was a t-shirt I got on clearance at Target and I love the color and the weight, but it was long sleeved, and who wears long sleeve, light weight t-shirts? If it's cold enough for long sleeves, it's too cold for t-shirts.
As you can see I cut off the sleeves at 3 quarter length and then used the fabric from the sleeves to make the neck.
I gathered it and pinned it around the neck and then top stitched it over the existing seam, so that this seam wouldn't show up.
It was very easy and very fast.
NOTES FOR NEXT TIME:
I would make the ruffle shorter, and maybe not as full.