I ask how they heard of me, its either Word of Mouth or they found me online. If its WoM then its typically go out and look at the property/job at the least. Some jobs I turn down right over the phone, others I ask them to email me a picture if applicable. Some I have to fish a little to see if they're tire kickers. I had one lady of foreign decent call me the other day looking for an estimate for "yard work". So i asked her what that meant, was it a project? a cleanup? mulching? She didn't know what she wanted done. Those estimates virtually never result in a sale for me. She was located about 45minutes down the highway from me in a very affluent area, but even then I told her that there would be a $45 consultation fee and I would help her assess the property "yard work" for 30 minutes. She said she would call back, that was a little over 2 weeks ago Guess my instincts were right on that one.
Stop guess-timating. Learn how to estimate and make money! $$$