Playing more Coup with new players, I find that honesty is a surprisingly powerful and common strategy. I do not know if the people I was playing with were hesitant to bluff, but almost every loss of influence/death was caused by false challenging someone else’s claim. It was a game of self-inflicted injuries.
I am sure I have played with other groups that lied constantly. I wonder what the curve is: start with minimal bluffing, because you do not know the game well enough to lie believably; lie shamelessly now that you know the odds better; go back to honesty how that people are expecting you to lie shamelessly?