What I'm getting at is how on earth do you manage to get Feudalism by approx turn 60?! Without capturing a large amount of AI cities with a hastily built army or going Gorgo.
1. You need your civic eurekas which is why building a settler and worker is important. You really have to concentrate on eurekas... and if you did not notice your craftsmanship was at 50% for 2 turns then that's an issue.
One quite clever thing with delaying slingers a bit is often people will declare on you which is a double bonus. An otherwise unreachable eureka and their army is near/on your turf so easier to deal with. How about a eureka for building a district?.... well the encampment helps there as you are crazy to ignore bronze working early.
2. You need monuments. Most cities you capture will have a repairable monument, capture those damn cities, know how you are going to take them and which ones are best to take. You do not need to take 10, take 4. And the first thing your settler builds is a monument... note I never said build one in your capital although feel free if you think you have it prioritised right or you cannot get 1 or 3 or 4
3. If you are next to a culture generating lux at the start, settling on it gives a huge % increase in culture. Something like Piopiotahi cannot be relied upon but is nice if you can get to it early, otherwise it's value diminishes over time.
4. Naturally first to a culture CS is a free monument... you can still take the CS but make sure you can do it fast as it's value is less at the start because you already have it's monument so to speak.
5. Of course there is always a pantheon to consider... starting with 2-3 bananas may be worth worshipping the banana god. Being a New Zealander, worshipping the sheep pastures is always pleasurable.
So... if you can get all 5 above you have done something wrong, namely getting number 5. You do not need all of the above but you need some and it is about practice. ... and eurekas are the most important.
This would be banned under Civ5 HOF rules:
It is an honour system based on exploiting.
If I repeatedly sell the city then that's wrong. If I capture 5 cities and one is rubbish of course I am allowed to sell it, as long as the intention is not the to attack that city in the near future.