On the last row of the collar, I knit it together with the first row instead of sewing later.

Confusing that the button hole instructions are before the collar. I thought they were to be done ON the collar, but they are AFTER the collar. The instructions would be better placed after the collar instructions to emphasize that fact.

No pockets.

On last round before joining for bottom, I did a 3-needle bind off of button band: put first 5 stitches on spare needle, knit around, put last 5 stitches on spare needle, knit next 5 stitches with each of the other 5 stitches on spare needles, marking beginning of round after 3 stitches, and continued around

Last three decreases of leg are halved. Last row before rib is (4 sts, k2tog). 14 rows of 1x1 rib at ankle.