Settling more than one city
Building a wonder that isn't Statue of Zeus
Taking a Policy other than Tradition opener when I've not got Military Tradition yet
Befriending a nearby City State when I could be laying down a Citadel that steals their resources and enables a unit to safely practice throwing things at people
Not burning down every single captured city that is not a capital because I want to keep Petra or something else not related to hitting things
Overstretching by attacking someone other than the nearest AI because they have a wonder I want
Not putting a fast unit on every captured city and losing resources to barbarians
Annexing a city to buy a Pagoda or something
Making a building that isn't needed for a National Wonder when there's a building needed for a National Wonder
Making a Caravan for a bit of extra food or gold when there's a location in its path where Barbarians can spawn
Slowing down an ideology beeline to upgrade already broken range logistics CBs to XBs
Not taking logistics ASAP because I'll eventually upgrade into Chu-Ko-Nu
Trying to make significant use of a UU that isn't a Berserker, Impi, Keshik, Camel Archer, Minutemen, Janissary, Samurai, Sipahi, Jaguar, melee Elephant, or Maori