-get to the thread EARLY. sort by 'new' and look for threads that make you think, "oh yeah that's gonna blow up". More important than making a good post is making one everyone sees
-post a meme. unless the sub explicitly bans them; they'll get upvoted almost no matter what.
-be the first to give an explanation of a technical or specialist subject that most redditors don't understand. it's fine if you're completely wrong, and you get bonus points if you claim to have some relevant real-life expertise
-be the first to respond "Huh, TIL" to the above
-if the post is about a dog, be the first to say some version of "he looks like a very good boy"
-if a post is about kids, be the first to say some version of "in all seriousness OP, you're clearly a great father/mother, keep it up!"
-if the post is about a video game, bitch about some widely unpopular feature of it (bonus points if it's developer scumminess stuff like in-game purchases, lootboxes, or DRM), even if it has nothing to do with the actual discussion