I love using this long tail style as a provisional cast on :
Hold the waste yarn and the project yarn simultaneously, or join with a slip knot to begin.
Place the waste yarn over the thumb, and the project yarn over the forefinger,
cast on in the long tail fashion.
Do not count the slip knot as a stitch.
Cut the waste yarn, leaving a short tail, and
proceed to work your pattern using the project yarn.
Don't forget to drop the slip knot if you used one.
When it's time to pick up the live cast on stitches, just snip the waste yarn every few stitches and pick up the live stitches.
Use a smaller circumference needle to do this, but remember to work onto the appropriate size needle.
In the image above, I left a yard-long tail of the project yarn at the beginning of the cast on, as the live stitches will be worked together with a 3 needle bind off.