[tapiwa]

Another useful method of opinion getting I have found to be useful, is to directly beg/ask for criticism.

"Please tell me all the bad things you can think about this idea." "Please tell me all the reasons you think this idea will not gain traction and will fail" "Please tell em why quitting my job to pursue this idea is a bad thing"

Questions that openly invite criticism are useful, since I think people think more imaginatively when they are being critical ... there are only so many ways to say nice things about something, but the insults can come from anywhere.

More than just finding fault with the idea, you will find assumptions you had implicitly made being challenged. So even if the idea is good, it might still be a bad idea to pursue it, lest you end up with a "the operation was a success, but the patient died" scenario.

If you have a cofounder, take it in turns, over two days, to defend/attack the idea. Defend your idea like Fort Knox on day one, and then attack it like it owes you money on day two.