How important is it to have a GP farm, especially early in the game?

For example, in my current game I have a city that is coastal with clams and floodplains. Since it was the first city I founded after my capital, I went with cottaging to turn this into a high-commerce city (that still with have enough food to work plains/hills thanks to the 3 food floodplains). However, in many of my games, I end up getting very few great people, and my question is: should I sacrifice early commerce and farm those tiles? Should I wait until the National Epic and then convert some of those cottages to farms? Should I build the NE elsewhere?

I know it may be hard to picture my game, but I'm talking in a general sense. At what point is it most effective to set up a GP farm? I seem to rarely get a city that screams GP farm at me, and so I proceed without setting one up. Thus, I don't want to try to force a GP farm where one clearly isn't. If anybody could give me some advice about selecting city spots and timing, that would be great. My main problem is that I always feel that by developing it into a production/commerce city (based on whether it has a river, lots of hills, etc.) using the food resources, I can be much more productive and efficient. Any help is appreciated! :)

You really need to be generating GP somewhere.

Even if it's just 2 scientists in a commerce city with a library, while you look for a national epic site.

The key to a proper GP farm is usually Caste System, made available with the Code of Laws tech. As each GP gets more expensive, you need to increase the number of GPP you're generating each turn otherwise they take longer and longer to spawn. To add more specialists you need to either be building more specific buildings in that city (markets/grocers/etc for merchants, libraries/universities/etc for scientists) or simply be running caste system, and slowly increase the amount of specialists you have by removing farmers. Simply put, it's a lot more efficient and effective to use caste system as your means to enable all these specialists than trying to keep adding buildings to open up the slots, as that can take a while and is dependant on a broad variety of techs being researched. The exception to this is of course are engineer and priest specialists which aren't available in unlimited quantities except via buildings, so if those are the type of great people you're after you'll be doing it the hard/slow way.

It's a good question and one I don't really have an answer for.
You probably need to play a few games where you make a dedicated effort to building a GP farm and see how it affects your game. You may really enjoy having GP arriving all the time and find it fun/useful, or it may seem like fitting a square peg in a round hole.

As for starting it early...your capital is almost always a high food city, and likely the best you'll have for a long time. The only situation where you're likely to find better early on are high floodplains cities. So if you do want to build a GP Farm early, your capital is often your best bet.

It can be tough to break away from a dependence on Great Scientists and a Bureacracy-fueled capital with cottages. It's a powerful combination that's fairly well understood by now and is part of the "canon" of Civ knowledge that's been accumulated here. Combine that with the Great Library (being discussed in another thread right now) and the timing of Liberalism and it creates an even stronger pull.

Improved Golden Ages, the Mausoleum of Masoullos, Great Spies, a higher upkeep cost for Bureacracy, introducing Corporations, and putting additional hurdles in the way of Oracle-Civil Service gambits are all ways the game has been tweaked to dampen the appeal of this path and entice players down others.

Corporations are one of the biggest enticements, and a good reason to save the National Epic. You may find you really want a specific corporation and you need a specific kind of GP for it. That can be a pretty good reason to delay dedicating one of your cities as a GP farm. In the meantime, having high-food city is always a good thing, as there are always units and buildings to rush with Slavery.

I know it may be hard to picture my game, but I'm talking in a general sense. At what point is it most effective to set up a GP farm? I seem to rarely get a city that screams GP farm at me, and so I proceed without setting one up. Thus, I don't want to try to force a GP farm where one clearly isn't. If anybody could give me some advice about selecting city spots and timing, that would be great.

Two slightly different answers.

Converting that early surplus of food into an early Academy has great edge odds. 90 hammers for a library and 34 food for the specialist(s) gets you 51 (+25%) beakers, then a 50% boost to your research rate (since the capital is doing most of the work in the early going). So the first Great Scientist can be huge.

The second one, not so much...

What this says to me is that you should farm a Great Scientist early, but you don't necessarily need the Great Scientist Farm early.

As for when to set up the Farm... first break in War Time production after Literature is researched?

To pipe in, when playing BTS you do not have to get an early GP faarm. Most of the time you should, but there are reasons to delay.

1) Leverage the NP and NE in the same city. Have plenty of forrest preserves, build the NP and NE and you are swimming in essentially any GP you want. Yoy also do NOT need happiness or health buildings, so build those that produce the specialists you want (market, grocers, theaters, broadcast towers, forges, factories, industial parks).

2) If you get ALOT of late GPs you have a very good chance to dominate the corp field. Even those conflicting corps (Creative and Mining) can be founded, just do not overlap in the samecity, and is nice toprevent the AI from getting them.

3) Late game GAs can be extremelyproductive, especially for Space Partsor modern weapon production.

To pipe in, when playing BTS you do not have to get an early GP faarm. Most of the time you should, but there are reasons to delay.

1) Leverage the NP and NE in the same city. Have plenty of forrest preserves, build the NP and NE and you are swimming in essentially any GP you want. Yoy also do NOT need happiness or health buildings, so build those that produce the specialists you want (market, grocers, theaters, broadcast towers, forges, factories, industial parks).

2) If you get ALOT of late GPs you have a very good chance to dominate the corp field. Even those conflicting corps (Creative and Mining) can be founded, just do not overlap in the samecity, and is nice toprevent the AI from getting them.

3) Late game GAs can be extremelyproductive, especially for Space Partsor modern weapon production.

I need GP early in the game. I start making them as soon as I have my library.

I never really made a gp farm. Because I do a rotation in my good city, one make scientific and the other prophet for example.

To make a gp farm, it would require a good city that can have at least 3 specialist. A wonder that boost the GP at 100% in the city or the other one at 50% for all city. The pacifism civic. And a philosophical trait.
I never tried this, but I should because it would make GP like mad!

And if you mix representation from the pyramid and the caste system with all that!!!

But at some point, I guess it will always take a lot of time to make new gp. I don't know what would be the point for this mad synergy.

An "early" GP farm without NE is pretty easy to set up - for example, just one food resource and two-three grassland farms can get you 6 surplus food at size 6-7 and you can run three specialists. Or run two and still grow.

The difficult part is that it can feel wrong to assign those specialists and cut that city's growth and building potential. Just remember that you are still building something - it's Great People. So as long as you need those great people more than you need a few troops or something, it's a good choice.

The first GS in particular is valuable and the first GP too if you have a holy city. Also you can trigger a Golden Age if you pop someone you don't really need, and THEN you produce GPP at twice the rate, so keep those specialists running.

Later in the game when GP are more expensive you can choose a really tasty site with heaps of farms and put NE there, but early on any somwhat foody city will do temporarily.

You really need to be generating GP somewhere.

Even if it's just 2 scientists in a commerce city with a library, while you look for a national epic site.

Most definitely. You don't need to have a dedicated GP farm very early, but you want to be getting great people points from somewhere so you can get some great people early on when they'll be most useful.

I'm assuming you are running a specialist-light economy otherwise (if you didn't, you'd essentially have multiple GP farms anyway).

It's preferable to have a source of GP, but it might be unimportant where they come from. Wonderwhoring and incidental specialists (when you want to stop growing but slavery is unappealling) can be enough so there's no reason to 'waste' perfecty fine cottageable land for the purpose of creating GP faster. The major drawback is that you won't have much control over which GP to get, so this doesn't work for a strategy that depends heavily on lightbulbing.

On the other hand, sometimes you have a spot that begs GP-farming by featuring the combination of mutiple food resources and junk land otherwise. This happens a lot near the poles when Tundra and Arctic tiles limit the amount of workable tiles but there are plentiful deer and seafood... Not good for production cities, limited potential for cottaging but abe to support a few specialists.