My check list for chargeable estimates; If I put on the tool pouch, charge If I have to go back to office and make calls and pricing, charge. If the stop is quick only within 1 hour than its free. Ballpark on the phone has eliminated alot of wasted time. I used to run around every sat. with no reward, people love to here "free estimate" but if they ask me several times if this is free....then I don't take job.