Here's a cut 'n paste from an earlier post of mine about taking cuttings:
I've rooted literally thousands of cannabis cuttings, but that was 25 years ago, and they were all sativas, and they were all the descendants of plants whose cuttings rooted well. I just started growing again and I wasn't sure if the old methods would still work ...
Well, apparently yes! I just took a couple small ones and they're doing fabulously. So, I'll tell you what I know - others know different stuff.
The principles are fairly simple.
1. You don't want to lose the siphon, so you get the cut-off stem in water within seconds.
2. When the leaves respire, they need to draw moisture and nutrients from the roots. No roots - so you want to ease leaf respiration.
a) that means you remove any leaves except for the apical cluster and a small fan - just leave the "top". This is one of the reasons you'll see clones with the fan leaves half cut off.
b) You also don't want bright harsh light on new cuttings for the same reason. CFLs are great - low heat, diffused light, etc.
c) You want to flood the new cuttings with humidity so they won't respire as much. Root them in some sort of enclosure where you can keep the moisture in.
3. Cuttings are best taken from the lower woody branches. There are more "rooting" hormones in the lowest branches.
4. Get some cheapo rooting powder that you can get from anywhere OR go with expensive specialty stuff - I never noticed any difference.
5. Use bland soil to root in. Fertilizer will kill a cutting. Peat starters are great, but in the 80s, I jus' rooted them in organic soil. Anything bland and non-chucky will work. I'm using those expanding, compressed peat starters wrapped in net.
Those are the basics. So, you have a cup of good room temperature water - no clorine, etc. Use either a sharp scissors or a razor blade and take off the branch at the base, using an angled cut - like 45 degrees - exposes more stem. Drop the cutting into the cup immediately. Water your peat starters or soil until it's good and soggy (again, no clorine, room temp). You want soggy soil compressed against the entire stem surface. Dip the bottom inch or two of the clone into the rooting powder - it'll stick - more is better. Poke a stem sized hole in the soil or starter, slide your cutting in, and compress the soil nice and tight all around it. Put it into your sealed rooting dome or whatever and stick it under "normal" light - nothing too bright or hot. Keep the soil soggy for a few days at least. You should be just fine.
I think there may be one more step that I'm going to try next time. Mycorrhizae are fungi that work synergistically with the root hairs to absorb nutrients. They form colonies when exposed to roots, and the earlier they form, the better for the plant. I'm thinking it might be a good idea to get some mycorrhizae powder into the hole that the stem goes into - should help the plant prosper from day one.
My cuttings limped just a little for a few hours and then straightened right up. They're gonna root jus' fine.