How I take and root clones and get 95-99% success rates...

Take a branch from lower part of the mother plant...ones with leaves low enough to become roots are best.

Take the cut branch to your cutting board and cut off the leaves from the lower area (while leaving the top with all foilage) at as steep of an angle as possible then place into the bottle of Clonex sitting nearby.
Let it sit in the cloning solution while the grow pellet is prepared (I stick a nail into the hole nearly to the bottom to clear out the hole so the stem will glide in without bending).
I then remove the nail and immediately take the branch sitting in the Clonex bottle and put a glob of solution into the hole, 2 times. Then I gently set the branch into the cube as deep as it'll go making sure the leaves that were cut off are well covered with Clonex and will be buried inside the pellet.
I then place into a recepticle (either the tray the clone kit comes with or I've found Dixie Cups work well to hold the pellet and cutting in place while it roots. The roots will grow thru the paper cup in about 2 weeks letting you know when the time has come for potting.

Once I'm finished with the above I mist-spray heavily and cover with the plastic dome and under the flouro's, as close as the lights can get to the top of the dome. I spray every 6-8 hours, every day until cuttings have rooted and become clones...then I put them in 16oz cups with soil and they get their first hit of ferts then...a very light dose (1/3 of normal strength) along with a splash of SuperThrive. They must be kept warm and moist during this time but the 3-4 mist-sprays/day allows the air to get exchanged and also time for inspections...other than that they stay under the dome all day/night.