When finishing a knitting
project, there are ends of yarn that stick out. "Knitpicking" is the act of removing these ends of yarn.
Knitpicking is given this name because it is tedious and time-consuming, and is something many knitters hate.
Knitpicking is done by taking a needlepoint
needle or similar and running the excess yarn under the inside of the garment several times, then cutting off the excess.