What NOT to do when querying a novel

As promised yesterday, here's what not to do when querying a novel.

I speak from experience since I did all these things three years ago when querying my first novel (note: this novel never sold).

Don't change from third-person point of view to first-person point of view in one week while
Don't email back agents who have the third-person point of view version and ask if they'd like to see the first-person
Don't mail the manuscript to an agent and then two days later frantically...