Very interesting topic- and a helpful one, too. I've used some of the methods you've mentioned, but there are a couple that are surprisingly new to me. Another method I've used is one based on a particular quality of the character, such as a continuous habit, character trait, or some sort of clue about their life that others may or may not know about them (I think you touched on this.) I've also taken a normal, simple name and tried rhyming it- whether it does or doesn't make sense, some of the names have turned out pretty cool.
Anyways, thank you for typing this up for us. I know I have trouble sometimes thinking of new, unique names for my characters, and I'll be sure to refer to this guide if I'm ever in a tough spot again.