Well, Abby Normal is still ahead of me on the board, and earned the spot.
I can give the same advice I was given: Make decent memes is the first one, but also utilize the social aspect of the site: In particular, comment and upvote on the memes you like. My cousin, who doesn't comment much, makes memes that people notice. He's around 120K in points. In January, he had about 100.
Commenting, though, is a big part of earning points, especially Meme Comments. People get to know you, and, if you come across as helpful and entertaining, they start looking for your memes to upvote. You get a big enough fan base, and they will upvote the occasional clinker that you produce.
Memes and GIFs on page one are a major source of rep building. This is where people get to know you, and even get to like you. One user on the top 100 Would have made the list a lot sooner had he been more sociable. That member chooses to be a jerk, which is why, even though he makes good memes, it took him well over a year to even get on the board. I deleted my old account last October, so I had to start from scratch when I rejoined in November, and while there are trolls that consistently tried to hamstring my efforts, I'd created enough of a fan base that I got on the leaderboard well before the aforementioned person. In fact, the person is well below me in that standing. Also, when commenting, upvote not only the meme, but anyone that replies to your comments unless they're being a real nimrod.
Summary:
1: Make good memes.
2: Comment and upvote on other memes. (Page one is good, but also, don't ignore the Latest featured memes. It's amazing how a first comment on a newly featured meme will actually increase your points, and standing in the community) Make sure that you upvote the meme (the "Comment tax") because if somebody sees you've commented, but there's no upvotes, they believe you don't care about being upvoted yourself.
3: Don't be a dick.