The two-colour long-tail cast-on works well for starting 2-colour brioche knitting projects in the round, and more. For brioche projects, either use a needle three sizes larger than your project calls for, or cast on over two of the project-size needles, as shown here.
This variation makes the bottom “nubs” all one colour on one side, and the other colour on the opposite side. To have the colours alternate on both sides, use this same method, EXCEPT: Start with colours reversed. Do Steps 1 & 2, then skip to step 6. After adding each stitch, change the position of the yarns, and ONLY pick up stitches through the loop on your thumb.
(You may also want to see my tutorial for How to Make a Slip Knot.)
You may want to check out the following patterns:
If this tutorial was helpful to you, please spread the word.