A reader left me a comment asking about yarn bobbins – I hope this helps.
I inherited the ones I use from a box of random knitting items that my mom gave to me (I think some came from a volunteer group and some from my grandmother). These are the ones I have, but this page has other options. You can also use other items around the house as needed.
I have used them when working with two colors (not stripes, but for fair isle? intarsia? whatever it’s called). The main color is still attached to the yarn ball. The accent color is wrapped around the yarn bobbin and you knit from that – it just hangs down in the back of the work and you can use it as needed. It keeps things a little neater.