Anyone? Beuller?

The exact details aren't publicly known, but it basically boils down to military victories scoring the best, and the more population, income, and military you have, the better.

There has never been any definitive answer posted anywhere. But here are a few things that are relevant.

1) Scores are calculated over time and not at the end of the game. Think of it as an area under the curve effect.
2) The early years are "worth more". AKA the same ship gets you more points in year one than in year two.
3) The three of the four components are obvious in their sources (economic, military, and research). The fourth (society) appears to be just population as far as I can tell.
4) While posting a game on Dec 22 of any given year looks pretty on the scoreboard, as the days and months are rounded down (aka DL game that has run for one year and 51 turns is recorded as one year), going to Jan 1 has the same affect on your score as carrying the game forward on any other turn.
5) You can post a final score to the metaverse twice.
6) You can see what score you would get by finishing your game and simply saying no to posting it to the metaverse. This lets you see where you are at without burning up a metaverse post.
7) Military scores the best. There is a ratio your score is multiplied by depending on the victory type. I've seen it before, but not sure where to find it offhand.
8) Difficultly also acts as a multiplier. If memory serves it's a .1 for every difficulty difference. I think one is somewhere around challenging, but I can't remember where one is for sure. So, assuming one is challenging, tough would be a multiplier of 1.1
9) If you do decide to push for points, I would suggest joining an empire or the metaverse league. Many of the empires are open (meaning anyone can join, like mine!) and you can often pick up some helpful stuff off fellow empire members. I think it makes the whole point thing a bit more fun if they can count towards both a personal best/challenge and some larger goal.
10) Check out the altmeta (in my signature below). It's a whole different way of looking at the metaverse.

Hmm. Direct link to altmeta, not just my character:
Alt Meta