which ever method you use: a cast on is meant to produce stitches for you. What matters is the amount of stitches you end up with. So if it says cast on 10 stitches, then you need to end with 10 loops over your needle.
And: long tail can
produce 2 stitches with the first "motion" - in my way of doing long tail it doesn't and I am more happy with my first cast on stitch than when I do the "start mid air" version. But that is personal taste