I've found that it pays to argue all sides of a discussion. Provide arguments in favor of the other's opinion, provide arguments against your own position, counter-arguments against your arguments, etc., all the while providing context and relative valuations of the arguments. When the other party is not capable of arguing their case or they need to be convinced that your case is superior, then this will not only broaden your view on the subject, but it will also give you a good chance of steering the outcome towards the solution you prefer.

Of course, if you are just discussing matters with smart colleagues to flesh out dis(advantages), then you don't have to do that much work and can just ride the waves.