I took two t-shirts I wasn’t wearing very often and made one shirt I like a lot!
I cut about two inches down from the armpit on my top light-grey shirt, and then one and one-half inches down from the armpit on my dark grey t-shirt.
I met them at the seams – these shirts were almost exactly the same size, so, thanks to the stretch of jersey, I didn’t have to make any adjustments to width. I put a pin at both side seams first and then worked the middles together.
I sewed a shallow zig-zag stitch with a 3/8inch seam allowance all the way around, using a walking foot and a stretch needle. Then I went around again, doing a wider zig zag stitch on the seam allowance. I’m guessing a serger would come in handy here : )
Definitely something I’ll wear more often than either of the two plain tees!