So many ways of doing this....some work some don't. I use 2" rock wool....soak them in a rooting solution for 45 minutes...put in a dome with a heat pad keeping the roots at 78f. I keep the dome moist but not dripping. As the rock wool starts to dry so will the dome. The rock wool will stay moist for 10 to 14 days. If no roots add a LITTLE bit of r/o water until roots appear.
Oh. keep the heat pad at 78f with a lamp rheostat. My .02. This method will result in over 90% success rate.