I'm trying to learn, too. I've only got one successful clone under my belt, and that one isn't even harvested yet. These clones were taken from that clone over a month ago, in Lucy's case, and about three weeks ago in Skye's. We have an 80 watt grow light fixture that they go under right away on autotimed 18-6 lighting schedule. We haven't tried the immediate dark method, haven't done much research into it.
I sprayed them at first, then tapering off so they search for water via roots rather than depend on the leaves.
They were in water in those Hershey's cocoa containers, so no light could hit the roots, until Lucy showed roots and I transplanted her into dirt. I followed the instructions on the ILGM website on how to treat them when taking cuttings, etc.
Lucy is doing well, but they both got that red stalk thing at the same time, which tells me that it was something I did, except that I treat them differently, each with her own light schedule, feeding schedule, etc.
As I typed this, it hit me. They are in a dark brown plastic container sitting in the window in direct/filtered sunlight. I went and checked, and the container full of water that I'm using to get her to root was 106 degrees using my infrared temperature gun. She'll be under artificial lighting for a while to recuperate, assuming she makes it.