Hey Joel… thanks for aggregating these tips. It’s easy enough to Google “how to write awesome headlines” and immediately become confused by the sometime contradictory advice.

One tool you didn’t mention is Emotional Marketing Value Headline Analyzer the found here: www.aminstitute.com/cgi-bin/headline.cgi

I use it all the time and I almost never see it on tool lists.

I’m not sure why but it seems like a natural fit for your list.