Buy a regular white tshirt, draw a diamond in the back, center with a pencil. then just start cutting strips down to the outline of the diamond. cut out a V from the tip of the diamond. then cut off the bottom of the tshirt and cut the neckline bigger.
I find myself jumping right into summer mode. Bust out the ol' sewing machine and I'm sure you'll be surprised by how much fun it is to whip up a whole new kids wardrobe with these 25 Easy Summer Play Clothes to Sew.