Starting a new ball of yarn
For my Honey is who is learning how to knit

The way I start a new ball of yarn (to begin a stripe or because the old ball is almost ended) is as follows.

First, I pull out a tail from the new ball that is several inches long. I hold the new yarn tail with the old yarn tail and tie them together into a slip knot. Then I pick up the new piece of working yarn and start knitting the row using the new yarn. The first stitch or two will be loose. Don't worry, you can tug them straight and tighten them up later. Assuming this is a flat piece, you turn and knit (or purl) back to the end where you started the new yarn. Tighten up those few loose stitches and continue knitting (or purling). The following rows should have normal tension.

I usually undo the slip knot after a few rows and just let the ends dangle. When I'm all done, the ends will be woven in and the loose stitches can be tugged and tightened more.

I had a coworker take pictures. I highlighted the tail of the new ball of yarn in pink and the new piece of working yarn in a blue/purple color.

Here I am with the yarn held loosely. The pink is the first 6 inches of yarn off the ball that will become the tail.


Here I am tying the light blue yarn (the old working yarn) in a slipknot with the new yarn tail. I cut the light blue yarn a few inches past the slip knot.


The knot is completed. You can see how the old yarn is tied to the new yarn. The yarn behind my needle is what I'm going to start knitting


And here I go starting to knit with the new yarn.


A couple stitches later. You can see the right side where I added yarn is kind of messy looking. This will be sorted out in finishing. Don't worry.


Two rows of stitches with the new yarn is completed. You can see on the right that I undid the slip knot and let the tails dangle. Those will be woven in later.