OP, I would extend mk4's advice and suggest you check out the posts of members who've earned a lot of merits--in particular, lower-ranked ones, because if you absolutely have to have a model to go by, those are the members to use.

I've been looking at a lot of post histories lately, and it drives me nuts when I see page after page of posts that are essentially the same length and have the same (minimal) amount of thought and effort put into them.  Personally, I wouldn't advise you to chase after merits but there are two things:

1.  Your posts have to stand out against the rest of the posts in whatever thread they're in.

2.  If you post in sections where the shitposters are, it's not likely you're going to earn merits.

As a caveat to #2, if you start posting in sections like Meta where a lot of merits are handed out but don't contribute much of anything, you'll be marked as a merit fisherman and may end up on people's ignore list.  So when you post, make it count.