This post is just a quick note on how I cast on separate blocks of colour to work in the intarsia technique. It is a technique I have used a lot in Animal hats to knit, and I am so sorry, I didn't include it in the techniques section.
My preferred method of casting on stitches is the long-tail cast on. I work the first block of stitches as usual; I make a slip knot in the yarn for the second block and place it onto the needle; place the yarn tails of the previous yarn over the tails of the new yarn; cast on the second block of stitches as usual. I repeat to the end of the row.
The principle is the same for all the cast-ons: place the slip knot of the new yarn onto the needle; place the working yarn of the previous yarn over the working yarn of the new yarn; cast on with the new yarn.
And yes, I knit so fast the tips of my knitting needles melt! Not quite true but almost.