In order to knit with more than one yarn you need to learn to weave-in the carried yarn, as you knit along. This is a 2 step process:
1. YARN UP – insert needle into your next stitch, put the new yarn between the old yarn and the needle, knit/purl with old yarn.
2. YARN DOWN – insert needle into the next stitch, put new yarn between old yarn and the needles, knit/purl with old yarn.
* Always insert the needle into the stitch before doing anything else!
* If you are adding a new yarn, do the above couple of sts before you need to use the new yarn. After knitting few rows weave in the tail you left (2-3inches) into the ridges on the purl side.
* Done with a certain yarn? – do the same as above and leave 3″ tail to tuck in later
* Need to carry yarn from here to there? – do the ‘yarn up’ ‘yarn down’ but only every 2 sts (instead of every sts).
Picture Knitting 