This is the method I use.
how to build a cheap bubble cloner
It works just about every time. I think I've had 2 out of about 150 not root. Hell, I even got rosemary from the grocery store to root in 7 days. The only differences I made to mine is, I have the stem of the clone about 1/2" into the water. I use a 4" air stone in the bottom and the little neoprene pucks sold for aeroponic cloners. I use straight tap water PH'd to 5.5-5.9 range. Normally 5-7 days later I have nice roots. 24 hrs of light from a T5 light. I have noticed no difference in amount of time for roots to show when I scrape the outside of the stem. So I cut them from the plant with a razor on a bias then straight into the water. Never have any wilting issues and never have to touch them again until they have roots. Easy Piezy Lemon Squeezie.