Elles from Misusu & More shares a free downloadable tutorial showing how you can make this awesome little cardigan tee for a baby boy. (Or baby girl, if you change up the colors.) She uses a t-shirt (or onesie with the bottom cut off) for the base of the shirt, and adds pockets and a contrast lapel collar. Her tutorial includes instructions for drafting and sewing the collar. Go to her blog to get it.
[photo from Misusu & More]