[slantyyz]

#13 is a tricky one, but important:

Don't be too technical. Gauge the technical ability of who you're talking with and match it.

I can't tell you how many times I've called customer support with a problem that I've done all my homework for the support call and then get greeted by a person who absolutely must follow a script.

You could tell them you restarted the server, restarted the process, etc., etc. but they don't care - they just force the script on you. I get that the first line of support needs to triage the caller before escalation, but annoying them right up front makes the experience very unpleasant.