Faire isle

i understand how to do the faire isle way of using two colors when knitting but i dont know how to start the use of two colors or how to go about doing that

like if im knitting say 4 rows of one color and then i go into the pattern ( im trying to do a skull) how do i add the color im going to use?

Leave a tail on the new color, 4-5" or so, and just start knitting. Once you get a few rows further, you can tighten up the stitches and weave in the end.

thanks, ill try that now!