I started looking through the older (pre-FFG) Civilization board game and mapping out the tech tree. I think I may end up going a bit more complex though and use the split tech and civics that the Civ 6 PC game uses. While that could quickly end up getting far too complex, I think because I would be dropping most of the eras, I can get away with some added complexity.
Tomorrow I'll start focusing on eliminating irrelevant techs (and maybe civics if I go that route), and start adding in a third tree for magic. I may need to weave those together because magic will influence what technologies develop (or in many cases, likely discourage certain technologies from developing).
Instead of pre-determined wonders that different civilizations race to complete, I think I will create generic categories like "religious wonder," "cultural wonder," etc. That approach makes a bit more sense, and I can have a set of bonuses available that civilizations can compete for instead. A created wonder might have a randomly generated number of benefits that it can have. Alternatively, when creating a city improvement, I may give each improvement a chance to be built as a wonder. A monument could turn out to be a cultural wonder, or a temple could become a religious wonder.
I should probably add something here.