So this tunic is something I made for my son in less than 30 min. I took one of his shirts that is baggy on him, folded it in half, and traced a somewhat bigger shirt onto one yard of prewashed red cotton fabric that was folded into quarters. The black line is the shirt and the blue line is aproxmently what I cut.
I then cut a key hole neck, sewed up the sides, hemed the sleeves, neck and the hem, and then zig zaged the raw seams inside and voila tunic finish and boy is wearing it already. Cost less than five dollars and took a half hour to do, and is big enough to fit for a couple of summers hopefully.