I've talked a lot about here about the failure of others to explain, and I have to agree with 1 and 5 but not the others. 5 in particular I've taken to calling the "method of nepocu tracing". (nepocu = nearest point of common understanding). Basically, fall back to the level of pre-requisite understanding, fix their shortcomings there, and then build off of it.

Likewise, most bad explanations I've seen seem to make no attempt to think about what it was like to learn a concept, and what key impediment stood in the way of understanding. (Some egregious self-promotion on what understanding means.)

I mainly don't agree with 3) -- every bad explanation I've heard is characterized by talking continuously without checking for whether you've met 5) and 1).