Stripes are an easy way to get started with using multiple colors in a project. Most often, you can simply join the new color at the start of a new row if knitting flat. If you're knitting in the round, however, you may notice that your colors "jog" when you change colors.
Today we'll talk about a couple of ways to avoid jogging stripes.
First is helical knitting. The lovely BrineyDeep of Ravenclaw has a great helical knitting tutorial on her blog. Helical knitting is great if you only want each stripe to be one row tall.
Alternatively, there's the slip stitch jogless stripe. this works best with stripes that are higher than one row. TECHknitting has a great picture tutorial on this style of jogless stripes. (and great tutorials in general!) There is another tutorial on TECHknitting that shows how to do a travelling jogless stripe so the fabric is less likely to pull when you are finished.
Either method is a great way to make your knitting full of color! If you're a video learner, check out this segment of Knitting Daily TV where Eunny Jang takes you through both the traditional slip stitch and helicial methods.