Tradition (the policy tree) 4 city opener into National College. NC should be done by turn 100. Go Granary - Library or just Library - Granary in your 3 satellite cities based on their production. You can always rush buy the 4th Library if needed since it often finishes very late otherwise. Mass farms in all of your cities and try and get to 10 pop in each of them by turn ~120. Beeline Education as soon as you've grabbed whatever you need from the early portion of the tree and get them in your 4 cities asap. Work those science slots as soon as it becomes feasible. That usually comes at 10ish pop which is why you need a lot of early growth. If you have 2+ cities or your Cap next to a mountain you want to get Astronomy next to crank out Observatories. If you only have 1 satellite city proximal to one then you can wait until Scientific Theory is finished to grab it. Next you want to rush Scientific Theory for Public Schools. Plant Great Scientists (GSes) that you produce up until then as Academies. Build your Guilds and work their slots. Secularism from that Rationalism tree enables them to generate science and you'll want the artists for various things. Musicians you can just create great works with but the other two you can use for great works or for their bonuses as needed. Using a Writer to rush Secularism is great for example. You should have Public Schools building by turn 160 at the latest. Buy one in your lowest production city if you have to but try and build them if possible. Work their specialist slots asap. Next you'll want to open Industrialization to look for Coal for Factories. Getting Fertilizer after is fine for more growth. Beyond that click on Plastics. When Replaceable Parts is finishing have your Cap produce Oxford. Make sure they end at the same time so you can use the free tech on Plastics. Start building/buying Research Labs. Fills their slots when you can. Once you've had your Research Labs built and all specialist slots working for 8 turns start bulbing your GSes. Get Satellites so that you can build Hubble while you research Apollo in a satellite city. I'm bad with the tech names but I usually get the tech that lets you build boosters first, then the "final" tech on the bottom that lets you build the cockpit (I think) and then I end with Particle Physics (the one at the top). Since the only thing that matters at this point is science I use my faith my buy Great Scientists to bulb. 2500 gets you 2 and 5000 gets you 3. If you have 3500 buy 2 and buy a Great Engineer to rush Hubble. If you only have 2500 then buy 2 GSes and just build Hubble. Your tech lead is too big and even though rushing it saves ~22 turns they're not 22 turns that matter. You'll still be sitting there waiting for Particle Physics so it's kind of pointless.
When you get Workshops work their specialist slots (again, Secularism generates science out of it) and if you can pop 1 GE that's usually fine. Get Porcelain Tower or Pisa with it. Both rock. Don't go crazy popping out GEs though. 1 tops usually.
For social policies max Tradition then open Rationalism + Secularism as soon as possible. You'll want to get Free Thought after. Finish the tree eventually but it's not required early on, especially if you're not making many friends. Open Order next and grab 2 happiness perks (+2 happiness from monuments, +1 happiness from Workshops/Factories/etc) and then get Worker's Facilities. Build Factories in all 4 of your cities. These are the key science policies. Nothing else in Order really matters (the Level 3 is marginal at best) so if you have good culture gain pick up Consulates early on and use that instead. You don't need to finish Order by any means and you don't have to finish Rationalism right away. You can leave the last 2 policies in it until your final RAs are completing. For Order Hero of the People and Skyscrapers are both really good but I mean happiness gets SCARY when other civs start adopting Ideologies. If you don't have a big happiness buffer (which you shouldn't) then I usually just get my +16 happiness. It goes FAST unless everyone around you adopts Order for whatever reason. So yes, get the +25% great person generation and -33% building cost policies first *if possible* but like if you think that +8 happiness is going to cut it when everyone around you adopts Freedom and Autocracy then you're going to be sitting at -10 over the course of 2 turns. Sit on your happiness buffer and thank me when you realize how it was just barely good enough to keep you afloat.
The only tricky part of policies is when to get Consulates (if ever). Whenever I can get Oracle (~25% of the time) I ALWAYS go Consulates after Tradition and then go Rationalism Opener + Secularism. If I don't get Oracle then I only go Consulates if I'm getting extra culture from a Pantheon, some city state allies that I made early on, some civ bonus, etc. If I'm just getting Culture from my Monuments and maybe an Amphitheater or two then I usually don't both getting Consulates since going Pat Opener -> Consulates -> Rationalism -> Secularism takes too long in my opinion but I mean maybe that's wrong and maybe I should always get it. Not sure really.
Mass farms. All farms all day. Don't bother with trading posts or lumber camps in most circumstances. I only build Trading Posts on jungles that aren't touching fresh water basically. I don't think that I've ever built a Lumber Camp. Mines you'll need obviously but like just spam farms on everything that you can (especially fresh water) and work those tiles asap. You'll need to work a mine or two for production obviously but like you want to emphasize growth.
Religion is tricky if you don't have a a bunch of natural help. Get a Shrine early on so that you can get the 10% growth Pantheon if nothing else. If you don't get a religion that's fine. If you do then get Tithe and Swords to Plowshares/Pagodas usually. I really like Tithe + StP though but Pagodas do help with Culture and Happiness. Still, the 10% growth pantheon is easily worth getting an early Shrine and the AIs NEVER take it. Obviously get better Pantheons if you can (faith from quarries, faith from natural wonders, faith from desert tiles, etc.) but if nothing else get 10% growth. I personally don't bother with religion unless I get a good faith generating Pantheon but I mean do whatever you want. You still need faith buildings to buy GSes later on but I mean you don't need to prioritize them in most instances.
Sub 250 wins do require good starting spots usually though. Still, it's definitely possible. I got
224 the other day on
Deity.