This is a great question, and I'm glad that you asked, since I am interested in hearing what people think about this as well. I suppose that word of mouth is generally superior to, say, just searching for a primary care doctor through your insurance provider's website, but I don't have any more specific ideas than that.

Personally, I can, and often have, put off going to the doctor due to akrasia, so I put a bit of extra weight on how nice the doctor is-- having a nice doctor lowers the willpower-activation-energy needed for me to make an appointment. I also think that willingness to spend time with patients is important, but I'd be more likely to think this than the average person-- I'm pretty shy, so I'll often tell my doctors that I don't have any more questions (when I actually do) if they seem like they're in a hurry, so as to not bother them.