Hi I tried looking for this but I couldn't get an overview.
lture - used to need to have a few cities with max culture buildings, lots of CS culture input
It still helps to have that, to speed up acquisition of Social Policies and to defend your culture against the tourism of the cultural leaders. Your global amount of tourism needs to equal (or surpass) the amount of culture each civ has produced since the start of the game, giving you Influential status with them. Influential or better (dominant) with all civs triggers culture victory.
To win, you have to focus on increasing tourism while not neglecting culture. It means taking measures to accelerate the birth of GWMA (Wonders like the HG, buildings like Gardens, SP increasing GWMA production like the Aesthetics opener, and the finisher that lets you buy those with Faith). There's also the Arts Funding resolution to pass in the WC, and Cultural Heritage Sites (=3 culture per WW).
The Aesthetics tree is another key with culture victory, as well as some religious beliefs that increase culture, and spreading your religion helps with tourism as you get a modifier for shared religion. Cultural Exchange increases the tourism modifiers by 15% for shared religion, open borders and trade routes. Finishing Aesthetics doubles the theming bonuses.
Passing your religion as World Religion in the Congress gives you +50% tourism for the Holy City.
means you have to be friends with people if you want to trade em?
No, it's an open market. Relations play no role whatsoever. You decide which GW you wish to trade and pick one you wish from those available and you swap them. If your GW doesn't suit the AI that gets it, it puts it up for trade again.
Also does this depend on ideology a bit?
Trading GW? No. Some ideological tenets have influence on tourism. Order/Cultural Revolution gives you +34% tourism with the other Order civs. Autocracy/Cult of Personality gives you +50% tourism with civ you're sharing a war with (as allies!).
There are buildings/National Wonders that are keys to a cultural victory. First there's the hotels (Refrigeration. 50% of cultural output from World Wonders, National Wonders + improvements are added to tourism, 50% more tourism generated by GW). Once you have hotels in all cities there's the National Tourism Center National Wonder (Telecommunications. like hotels, but 100% increases). Finally there's researching the Internet, that doubles tourism output.
You need cultural Wonders to get slots for more great works, and museums to park your artefacts. Effeil Tower also gives you +12 tourism.
You need to perform very well in science (a near universal rule in BNW), and avoid letting civs run away in science (don't neglect Research Agreements... if you refuse them the AI will get one with his other friends) In the late game (from the modern era) you need to focus on the top of the tech tree, and watch out for an AI beelining to get the Great Firewall, with negates the Internet.
Avoid giving/selling open borders to anyone too strong culturally. Rather purchase open borders with them, which will give you a tourism modifier with them.
I might miss a few things, but that's the basics.
Do I need to get factories or moderm era first to get pick of this?
Every Civ gets to pick one of the three after they built 3 factories or when they reach the Modern Era. If you're first to pick an ideology, you get 2 free tenets (similar to Social Policies and gained the same way) when choosing. The second civ to pick that ideology will get one free tenet. The third and more don't get free tenets.
Diplomatic - best to host world congress.. and get lots of friends?
The AI very rarely votes for a player. Apparently it might agree to do so if positive diplo modifiers are about maxed out. Otherwise you get an AI to vote for you as World Leader if a civ was killed off by another player and you resurrect it by liberating one of its cities.
To win diplomatically you need to have as many CS as allies as required. Hosting the Congress gives you extra delegates. Passing World Ideology gives you and all those who share it extra delegates. Globalization helps you as well, as after its discovery every spy you park as diplomats in a foreign capital gives you one extra delegates. The Forbidden Palace permanently gives you 2 extra delegates.
Best to be nice to lots of Cs's?
Get as many as allies as possible, yes.
Somehow have policies that you put up for world congress that people are likely to agree to?
This will help to maintain good relations, but not achieving a diplo victory. In fact you often have to upset the AI with some resolutions like Arts Funding, World Religion or Ideology. But good relations are better, especially if you don't yet have enough CS allies - you can't bribe them if their ally declare war on you...
Also which Civs are best for them?
Several can do either. Poland is good for getting Social Policies.
Venice is also very good for CV or Diplo victories (you generate so much money it's very easy to get all the CS as allies), and fairly easy to play.
