Love the colors, and the fresh sporty style.
I had this yarn lying around and so cast on sufficient stitches for a 12yo neckline, first flat with increases then joined in the round after the p1, k1. For the raglan incr I did a simple kfb, sl m, kfb until desired length, followed by 2 rows without increases and then the separationo f sleeves and body. This way I had the beginning of the row in the front center, which is ok but not optimal for the color changes, in another shirt I would move that to under one arm.
I BO the sleeves directly as I love this length - but then had to pick up stitches for a k1 p1 cuff later. The very short, especially when rolling up, just looks very girly. And maybe not confortable enough for kids, anyways.
The stripes are 10 rows deep each. After the separation for the sleeves it was just mindless stockinette in the round, I finished it in numerous videocalls & tv sessions. :-)
The yarn is very classic cotton, which is not my favorite but goes with the style I want to create, both in terms of look and especially touch. The colors are beautiful and almost a bit shiny, I hope they stay this way.