I’m working on an amigurumi doll. I need to buy eyes for the head, so I can’t work any farther in the pattern. Half the head is done.
I want to start on the body, but need the same yarn. How can I cut the yarn off to work on the body of the doll, then go back to the head later?
If I didn’t make the question clear enough, just ask me to clarify. 
You could find the other end of the yarn and start working from there. Or you could pull out more than what you think you will need to finish the head, then pull out a little more and cut it, then start the body.
Or if you have another skein of the same yarn, just use that for the body.
Have fun!
MGM
I believe all you would have to do is leave a few inches of a tail or so and cut the yarn, and when you come back to it, just start up where you left off with your same yarn again, kind of like changing colors, but obviously with the same yarn. Thats what I would do anyway.