Okay, I've got the knitting down....now I want to try a 2 color piece. I know how to cast on, but I'm confused as to how you introduce the new color? Once I have, say, 20 rows of this color, then how do I bring in the new color when it's not attached to anything? Do I just tie it on, but then how do I get the other color back? AHHHHH!! I'm wanting to do a scarf that is striped..... Please help!