For my 18-mo-old nephew. (My gauge puts it between 2-3 yrs sizs so hopefully it’ll fit.)
Based on DROPS/garnstudio pattern (pic below).
Yarn is from recycled thrift store sweater (cashmere soft cotton). (Frogged, skeined, washed, wound.) It was so thin (pic) I had to use three balls of multiple threads to get something akin to worsted weight. Needless to say, working both fronts at once meant six simultaneous balls. Lucked out with virtually no tangles.
Added an inch to sleeves being his dad, my bro, is 6’5" and has super long arms. I opted to make lower edge ribbing hang straight rather than pulling in…and did traditional pockets. I also chose to place the buttons/buttonholes like ‘big guy’ sweaters.