The most consistent opening for me is slinger->builder->settler->trader. This opening will give me inspirations and eurekas for archery, craftsmanship and early empire, and even if I'm under attack, with Agoge and 2 cities, I can spam units like crazy. I also usually have enough gold to buy a couple of units if the need arises, since I don't use it for anything else that early. Once my capital's pop is enough to work the best tiles, I pop the settler production policy and keep spamming them till turn 100, only stopping to place districts down. If I want to go to war, I get 5-6 warriors and 4 archers first, and continue developing my cities. Very rarely I use other cities to build settlers. I will have to be delayed in some manner to do it. My district priority is Commerce > Campus > Industrial > Harbor. Of the district buildings I prioritize science, and don't bother with the others for a while. I usually build workshops while teching industrialization. I also like to prioritize food and improvements that give housing in the beginning, making sure that every city can reach at least 7 pop before switching to production. When settling locations, my criteria are to be in range of my capital's IZ, and their IZ to be able to cover 2 additional cities, and have 1 or 2 good food tiles. Food resources and marshes are the best early, because if you have lets say 2, you can reach pop 5 easily and then harvest them, reaching pop 7. Rainforest can work too. The exception to that rule is if a city has lots of hills. In that case I'll try to settle it later and reroute as many trade routes as I can to develop it fast. Last but not least, monuments aren't super important to get fast, but getting all possible culture boosts early is very important. Stuff like pantheons, meeting cultural cs etc.