To Honorius, The primary source of most points for advanced players is fighting. Every fight adds points. Each Era higher more points per fight. Fighting become noticeable for points once in Future, and really climb in the Space Ages
For new players Great Buildings (ad regular building count for points too) may be a larger part of the points... But as you gain in fighting strength, and move up Eras, fighting takes prominence. You also get points for Goods spent. Both to build GBs, and from spent on Negotiations