I've been binging that guy's videos the last couple days. They're a goldmine of information. Here's some of what I've seen there as well as my own observations for achieving quick CVs. There's a lot to cover though if you want a complete ELI5.
China is a beast at getting the quick wins, for several reasons. They have a much easier time getting wonders, using sacrificing their (buffed) builders to get them quickly. Very helpful for getting a lot of early game wonders (Pyramids, Oracle, Apadana, Colosseum. Explained more later). China also has a very early and easy to get unique improvement, which lets them get easy era score, which can really really help getting a classical golden age (again, more later). It seems no other civ quite has the same synergy for the quickest wins, though others are certainly still very good.
Essential stuff: There's a couple things I'd consider "essential" for quick CVs. Getting Goddess of the harvest pantheon is most important. This gets you absurd amounts of faith, which you use to get more faith. Coupled with this is getting a Classical era golden age, with the Monumentality dedication, which lets you buy builders (and settlers and traders and later naturalists, but mostly just builders) with your huge faith amounts. The problem is getting that early golden age. Missing it probably adds 20-30 turns on your win time. The era usually starts around 48-50 or so (assuming deity). By that time, you should have 3 cities up, built pyramids, and explored a lot. Getting tribal villages helps era score a lot. Also finding wonders (and settling near them) is great help. UI or UU if you need it. High-agency bonus campus/theater square can also be a good source. With some practice you should be able to get the golden age pretty consistently. If you miss getting the pyramids, that's probably a reroll, since it just helps so much. You also need plenty of room to expand. And tons of tiles to chop for faith and production. Everything else isn't quite as important.
Wonders: as previously stated, pyramids is most important. It can be tough to secure though. You need desert, which isn't always nearby. You may need to build it in a second city. Aim for getting it turn 35-45, maybe? It varies on competition, but earlier is always better. After that, look at Apadana, which is pretty good, but I'd only consider getting it with China, since they can get it so easily. Sometimes there's a lot of competition for it though, so it's not guaranteed. I'd say skip it with anyone else. Next is Oracle. Usually not much competition. Oracle pairs extremely well with Pingala, his second promotion. Stick him there and get huge GPP. A little later is Colosseum. This is maybe turn 60-70, so in second phase of expansion. Place it so it has as many cities in range. It's a huge culture buff, and you'll never have to worry about amenities again. Kilwa Kisiwani is pretty good, go for that when available. Much much later is Cristo Redentor. That's all the important ones. Eiffel is good, but by the time you get it, the game is usually over. I personally like Mausoleum, for extra engineer charges, which you use on other wonders. Wonder spamming isn't really bad. Just don't let your infrastructure lag (districts and then buildings). Sometimes you can get enough early game tourism to really help quicken CVs.
Great people: the only one you really *really* need to watch for is Galileo/Darwin (they're both renaissance). They give you a huge boost to science, which can speed your victory up 10+ turns. Get all the GWAMs you can, buy them (with faith) if you have to if another civ is close to them. Don't let any civ start snowballing with their culture. The other ones types are nice, but not really important.
Phases of expansion and builds/techs: I'd say there's 3 phases of expansion, beginning, classical era golden age, and filling out the rest of the land. It's important to get going quickly, so you can start snowballing sooner. Beginning phase lasts until you get to the classical era. Exploration is super important, along with plopping down 2 cities. Possible builds: Scout>Scout>Settler>Builder... Scout>Settler>Scout/Builder>Builder>scout... depending on how fast you need to get your cities down before your neighbors get good spots. Be aggressive with your placement. You can fill in the gaps later. Just be aware of loyalty concerns. Go mining>masonry for pyramids asap. Stone/marble is extremely beneficial to have nearby so you can build a quarry for the eureka for masonry, which will save you 5-10 turns on the tree. After that you'd probably want to go pottery>irrigation for improving (and selling) a lot of nearby luxuries. Civic-wise isn't super important. You want to get your pantheon asap, so slot in god-king if you haven't met a religious CS first. After you get your pantheon, forget god-king (because it's terrible) and put in urban planning (which is one of the best cards in the game). Top path of civics tree is probably better first, for agoge. Just aim for political philosophy. Build pyramids, get government plaza, explore explore explore. There's a bit of room for experimentation for going for Drama & Poetry or Mysticism before PP. Just get every boost you can and don't waste any turns you don't have to Golden Age: woohoo. Now''s the fun. Go classical republic. Get ancestral hall asap. Slot in settler production card (along with urban planning because it's OP). Build settlers everywhere. Buy builders. Chop. Buy more builders. Chop. Buy settlers. Get Oracle. Get Colosseum and forget about amenities. Build campuses, theater squares, and commercial hubs. Go really wide with your city placement first, then fill in holes. The rest: I'd say it starts with the medieval era. You should easily have earned another golden age (and chosen monumentality again). Look for more places to expand cities. If you ever are debating whether to build another city, just build it. They pay for themselves (with the free builder from ancestral hall and then chops for faith). Look for places you can get tons of chops. The rest sort of plays itself. Expand infrastructure, etc. Get your great works going.
Random notes and tips: there's a lot of random tips that don't quite warrant a section themselves.
If you don't get goddess of the harvest pantheon, it's not necessarily game over. There's still a lot of really good ones. Like Divine Spark. It's just that none of them come close to the amazing combo of GotH + Monumentality.
Religion is (99%) never worth getting. It just doesn't pay for itself.
You can change policies twice on the same turn for free when you switch governments (notably chiefdom into classical republic). This is mostly only notable for Land Surveyors for cheaper tile purchasing. Slot it in, buy all the (good) tiles you can, change governments, put something better in instead. Similarly, swap in other cards for big purchases like serfdom or mercenaries, then swap out asap, since they're useless when you're not using them.
Most of your gold is going for tile purchases. Buildings are usually too expensive to warrant buying them widespread for a large empire. Again, use land surveyors for big tile grabs, then quickly change it out when you spent all your gold.
Sell all your amenities as soon as you can (early game most importantly). The bad effects of negative amenities is trivially unimportant early game. It's a lot better to sell your amenities to neighbors. That's extra gold you can spend and they can't.
You can buy their open borders for 1 gold, and sell yours for 1 gold per turn.
Try not to chop anything unless you have Magnus there. He's just so good. He's been nerfed, but still really good.
Have a group of builders follow wherever you put Magnus. It's much more efficient to have 6 builders chop everything in a city in 1-2 turns then 1 builder chop everything in 6 turns. It's sort of funny. Your builders are just like a devouring swarm.
Mid-late game don't be afraid to settle in heavily loyalty negative areas. That is assuming there's a lot of resources nearby for you to chop. Slot in Magnus asap, move your builders there, grow the city (chop marsh/rice/wheat/rainforest). A size 6 city shouldn't have much loyalty problems with a governor and at least one of your cities somewhat closeby. It's a bit dangerous, but you can quickly get a good feel for what's safe and what isn't.
Late game exploring oceans is pretty useful. Even 1-tile islands can be super good. They usually have an abundance of fish/crabs, which are great for chops. They easily pay for themselves, faith-wise. And buying the tiles is easy because crabs give so much gold late game.
Be mindful of city-states and their quests. Try to get suzerain of important helpful ones. Early culture CSs are very very helpful.
Don't be overly-concerned about a huge tile adjacency bonus for a single district. The good spots are often really far out and not worth spending the gold. It's usually much better to build district triangles of your campus/theater squares/commercial hubs. Don't throw away free adjacency though, like rivers with CH or a mountain + campus if it fits well for your triangle.
Along with the last point, it's really good to plan two (or three) nearby cities' districts close to each other in the middle for maximum adjacency.
Settling on amenities is amazing. They provide a huge free tile boost to your capital, and you immediately get the amenity without having to improve it (or even have the tech required yet). This lets you sell them as soon as possible. The only luxury I probably wouldn't settle on is marble, so you can improve it for the eureka for masonry.
Settling on wonder-adjacent tiles is double-plus-good amazing. Their yields are often incredible and last the whole game. It's even debatable to consider moving your capital away from fresh water to settle next to a really good wonder. There's also the extra era score for doing so.
The purple GPP cards are almost never worthwhile slotting in. There's almost always something more relevant to what you are building. You'll be earning a ton of GPP anyway, and you can just buy one with your faith if you need to.
If you're ever debating whether or not to build another city, the answer is yes.
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Wow this post really ballooned. I hope people find it helpful. There's a lot more to discuss about mid-late game.
