Clones-Thoughts, Tips, Help

So i'm messing around with cloning and am looking for any tips, ideas, thoughts on cloning.

This is my third attempt,( the first yielded 75%, 2nd 50%) I am using a mixture of perlite and vermiculite 50/50 with a humidity dome. These methods were not utilized previously, just root powder and dirt. Also i'm trying olivia's rooting gel this time and cut the clones with new technique i.e. clones with soft stalks as opposed to woody ones, clones with 2 or 3 nodes on them, and scrapping the bottom of the stalk where it gets covered with the rooting gel and long angled slices with a barber's razor.

Also 18hrs vs 24hrs light for clones?

10 days or so before rooted enough to transplant?

There are people much more qualified then me, but after my first attempt failed I bought the rapid rooter with dome. Followed the instructions exactly and added one extra step. I scraped off the outside of the stem and after 10 days they have all rooted. First time I tried it with my own home made thing without heating pad. This time heating pad and daily misting under to cfl's. Piece of cake.

I have been growing/cloning lots of different plants my whole life, just started with cannibus. I keep my clones under 24/7 light under a dome 55% humitity they are in the little clear drinking cups. I keep the tops of the cups covered as though no light can get to the roots...I leave them in there until I can see roots on the sides of the cups......I have never lost one! they take on average 8 to 12 days before I can see the roots on the sides of the cups...only then do i transplant my babies oh the light is very dim, 20 watts floresent tube

why do you prevent the light from hitting the roots?