Phase 1 = expansion phase
It is all in the title and whenever you make a decision during this phase think of the title. For example I have finished a monument in a new city and having places down a campus at the city founding I could now complete that... but I also need a granary, which do I get? Well the Granary helps with expansion but the campus does not so do not build the campus yet. If you have a granary and do not have anything else to build but a campus, build it but do not chop it, there is good reasons not to.
During the expansion phase you should be getting out as many settlers as possible and killing opponents if not playing peaceful, these 2 are primary. When you get a new city you place down a campus straight away because it is cheaper right? Well if you have built 3 campuses you start shooting forward and if you exceed your culture numbers then you are paying for more for that campus than you need. The cost of a campus is the higher if the tech discoveries/total techs is higher than the civics/total civcs then you have pushed science too fast. So only finish what you need at least in the expansion phase, tings change completely in the planning phase. This takes me on to what a great player has said a few times... building a city after about T80 if planning to finish at T150 is fairly pointless unless you can fast chop it. So push those cities during expansion, placing your science district down at founding time. Now perhaps you may need a bit more culture and if so start with a theater in a couple, maybe slotting the +2 great writers card.... highly underrated. I did not do this because I could see a good coliseum spot... I think I got 8 cities ... and Coliseum is very important as is pyramids if you do not get harvest (after the patch with harvest gone you will always need pyramids) Planning location early is important. I stopped producing settlers when I had filled my coliseum ring. (coli not built yet). Harvest really helps get settlers out because buying them with faith is great. I got 1 city out early then stopped until I got the 50% settler card but limited them until I got my govt building a bit also. I think by about T60 I only had 1 campus built for the plaza inspiration.
In the expansion phase you just do not know exactly how things will pan out because 'stuff' happens so you really concentrate on what I said + maybe a few others things for culture victory. Another key part of the expansion phase is culture and in my real game I never got to find a culture CS which is the best CS to get an envoy in early. Culture is so important early game this is why we push monuments as first builds in new cities but you should never sacrifice a university chop for a monument chop, if unsure do not chop. With harvest you do chop a bit early because you need faith to get settlers and remember chopping rice/wheat/crabs/cows is good enough. Planning Eureka's and inspirations is also an all game thing make decisions about what you can and cannot get.
Phase 2, planning phase
So when is the planning phase? roughly when you get to feudalism, this is so much more important for the extra builder chops than anything else but it is so great in so many ways. Now is the time you start chopping because your builders have more charges but also your chop is worth more.... roughly 80-120 are the most efficient times to be chopped as analysed by
@Sostratus once. But do not chop immediately, you have been holding back and now you want a few fast discoveries/civics to increase chop rapidly. If culture is still leading the chop then there are some 1-2 turn civics at this time that also have envoys and you did not really need the CS power in spades before now... but with chopping in all of these science buildings we need to get at least 3 in each, more of a challenge. So during the planning phase you need to find a good chop place for Kilwa ASAP and this will also give 3 more envoys. You need to be working out what you need for victory, looking at the tech and civic trees and checking how soon you need each eureka and inspirations. Where you need a spaceport, what governor promotions you need when. How much gold you need by when, everything you need to get there... chop everything you need, ou need to get most of your Unis done also... seriously, at T80 I was on like 36 science then bam into the hundreds... at T90 I was on 100 so the last 17 turns before you see it at T107 was a massive increase and this is another noob mistake. They compare themselves to other civs at T80... like Duh, I would hope you were less, you are doing well if you are less.
Phase 3, execution phase
by far the dullest phase of doing and clicking next turn. One key thing during this phase if getting cities to 10 (food chops at 8 pop are a great way) upping adjacency to 3. Checking your cities are not growing more than needed to keep happiness good, using specialists where you can and using science projects in cities as the default if there is nothing else to do. Keeping an eye on everything.
So looking back at my game I ws playing the planning phase in a rush during some work issues and forgot stuff. The faster you play the more you will forget and I like to play fast I get bored easily. I cannot remember which person from the Chinese forum it was but they said the lower they played the faster their game turn finishing. I am not competitive, I understand there is no such thing as best to me, just how much I enjoy life and I like it in the fast lane.
Do you want me to replay the game 10 turns at a time explaining those 10 turns? It is probably overkill but I would get a GDR in under 150 doing it that way... we have a new patch coming and may not finish as I get quite busy, especially with family.
So
@RoboEmperor look at this quote from you in your opening statement and read it well and you will have your answer
I just settle a city, build granary, build campus, build campus buildings, build commercial district, build commercial district upgrades, and then once all that is done build settlers
