Ideas are like stars in the sky of our ever-expanding universe. They seem to be born out of the darkness and to proliferate to infinity. However, similar to an unaided (or even aided) view of the night sky, where it is difficult to discriminate between each star or to see a pattern in their configuration, the quality of an idea is also hard to evaluate, as is its relation with other ideas.
People often resort to signals such as pedigree, accolades or some other external marker to help determine whether an idea is good or not. This default approach often leads people astray. Fundamentally, a great, new idea would be hard to measure since there would effectively be no precedent for it, and it would bear relatively little resemblance to whatever sources inspired or informed it, regardless of how they were originally received.
Contrarily, bad ideas, which should have long expired, can continue not just to live but to form the basis for other bad ideas, in other words, result in the proliferation of bad ideas, if they had been deemed by the powers that be, which can be more interested in maintaining the status quo than rewarding intellectual merit, to be good ideas.
Ultimately, from a theological perspective, only God would definitively know whether an idea is good or not. The rest of us have to evaluate them in some other considerably less omniscient way. What way should that be? How does one assess the merits of an idea?
I would argue that, to the extent that one can, it begins with purging the mind of bias and then comparing the new idea with existing similar ideas and objective analyses of their effectiveness, from positive and normative perspectives. There should also be a strict evaluation of the absolute merits of the idea itself; albeit, this is easier said than done.
Ultimately, there is no perfect method since there are no perfect people or perfect ideas; however, the goal should be to identify the star ideas and to create a constellation of the best ones, which should yield, by all objective measures, a better world.