People are afraid of the word 'salesman' they think it has negative meaning. It doesn't.
To me, salesman means that I care. And being the best salesman means I care more than anyone else does.
Don't be the guy that goes to a job, fixes only what you were sent there to fix, and walks away. DIAGNOSE EVERYTHING.
You have no idea how many customers I've been able to help BIG TIME by just giving a fuck enough to look around and show them other things that need to be fixed.
Start caring more than anyone else and I promise you will have more success, you will have more job satisfaction, and you will make way more money.