Search Results: calling after a date

I have had at least 75 first dates as a result of online dating, and a few were horrible (pictures not current, lied about age, etc.) Most of them weren't that awful, but we just weren't a good match. When I got some experience with rejecting a lady, I eventually decided that the best thing to do was to walk the lady back to her car, no good night kiss, no hug, tell her that I enjoyed meeting her, she seems like a nice lady, but I don't think we're a good match and I wished her good luck with her search. That stopped any expectations from developing and avoided the appearance of misleading her in any way. Maybe that isn't how she wanted to hear that message, but I thought it was better than taking the easy way out by texting or simply not calling her again.

If you were the lady on one of those first dates, how and when would you want that message conveyed to you? If you were the guy, how do you think that message should be delivered?

(Yes, I know that it isn't entirely up to me to decide whether to have a second date; a woman can reject me after the first date, and I have had that experience. I'm just asking about this from a guy's perspective. If you want to ask about how a girl should reject a guy, you can post your own question.)