Which is a best practice for creating effective ad text?

[lordp]

Hi friends,

Use all capital letters in the headline.
Make sure the headline wraps to two lines.
Write several ads and see which one performs the best.
Capitalize the first letter of each word in the headline.
End the headline with an exclamation point.

Too much optimization will only increase the chance of getting removed from the SERP's. If Google sense too much optimization then it will just remove the head title as whole and replace it with whatever headline it seems fit.