One of my least favorite parts of finishing a knitted piece is having to weave in the ends of my yarn, which is what I use tapestry needles for. If the yarn I am working with is wool and able to felt what I prefer to do is called ‘spit splicing’. Spit splicing is when you use spit or water (spit is more convenient) to felt two ends of yarn together so that you don’t have to weave them in later.
In the event that I can’t spit splice my ends together, I use a tapestry needle to weave them in. To weave in ends on a knitted item I thread the yarn through the needle and then weave it in to the back side of the knitted fabric to secure it. It is really important to weave in (or spit splice) the ends of a knitted item because if you don’t it is likely that they will begin to unravel.