The idea you dismiss instinctively may deserve a clear account of what exactly you reject.

Instant rejection is usually a feeling wearing the clothes of a judgement. You can know within a second that you disagree and still be unable to say which part is wrong, which usually means you are reacting to the source, the tone, or the company the idea keeps. That is not always mistaken, but it is not yet thinking. Being able to state precisely what you reject is the difference between a position and a reflex.

Take something you dismissed recently and write one sentence naming the specific claim you deny. If you cannot finish the sentence, you have found something worth examining.