Currently, I have my eyes set on a couple of schools, but I have no idea what I need to do so I can get even the slimmest chances available! What would get me a writing major for a school like Hamilton College?
Hamilton doesn’t offer a “writing major.”
As for your question, well, look up Hamilton’s GPA and SAT/ACT averages. If you want a good shot, be at or above the top end of those ranges. Then write great essays, do a bunch of meaningful and enriching activities, and all the usual stuff. @Shinochi
If your record indicates you are qualified for Hamilton, then you may have substantially greater than the slimmest chance of admission. If your record, in contrast, does not at least approach that of the core of their recently accepted students, then you may have essentially no chance at all. With a brief assessment, such as that suggested above, the scenario that applies to you should be evident.