While knitting my Creamy Feather's Scarf I found a knot in the brushed mohair yarn I am using. I had really hoped this wouldn't happen as I have struggled to tidyily weave in or knit in ends. As I am knitting the two halfs of the scarf independently and then kitchenering in the middle to ensure I get a pretty cast on ruffle and the right feather and fan pattern, I hoped to not have to join yarn together. I did a search for join techniques and found the felted join!
Knitting Help's Felted join video
Essentially you split the ply, wet the ends and felt the ends together by rubbing between the hands. Crazy Aunt Purl has a great blog post here.