I started a Fair Isle project on circular needles that has 4 colors to it. I am finished with color A, what do I do with it? do I tie it off? Any tips tricks and cool ideas would be very helpful.
No, don’t tie it off. Fair Isle yarns are carried throughout the project. Here is a video of how you carry the yarns.
http://www.philosopherswool.com/Pages/Twohandedvideo.htm
Even if you don’t knit two handed fair isle (I do) you can still see how to do it.
Cool. I wish I would have had this video when I started! 
Thanks for the help and the link.
You’re welcome!