What to do when I find a duplicate question - often already marked as duplicate, and I find that the question is indeed a duplicate, but much better answered in a different question, so that it may be much easier to answer?
As an alternative to leaving a comment or posting a message in chat asking a gold-badge user to add or change the duplicate target, you can flag for a moderator to change the duplicate target. Moderators also have the ability to modify duplicate targets.
Additionally, if you're the author, and there are pending votes to close as duplicate but you find your answer in a different target, you can vote or flag to close it as a duplicate yourself for that target, and then approve the duplicates. This will cause both targets to be shown. If you feel that the other target is completely irrelevant, you can flag your own post for moderator attention requesting that it be removed after doing the above.
If you have gold badge tag powers you can add the link to the duplicate banners, if you don't you might suggest a comment (as always you can ping users involved at the post using
@<username>), or ask someone who does in certain chat rooms.