Depends on the map and starting location, i don't always have good and enough CS candidates for friendship in my vecinity or even on my continent. Take siam for example, spawning next to a few maritime/culture CS is much better than spawning next to a few mercantile and militaristic (does SIAM even get anything extra from these?)
Always Huge, always Pangaea, always Marathon, always 41 City States. The Pangaea is because it seems that if you have world-spanning oceans, you end up having less develop-able land tiles. And Pangaea still has an abundance of inland seas so you can use maritime features, as well as a fair-sized ocean that abuts the West and East edges of the map.
The long term strategy doesn't really require useful CSs to spawn nearby, or even any CSs nearby. All you have to do is thoroughly scout out the entire map (which on Huge only takes about the first 3,000 years

) -- which is something you should do anyway, regardless. Along the way, work on beFriending/Allying the Culture CSs = faster border growth and faster Social Policy acquisition. It's beneficial to buddy up to the other CS types too, but the most useful will be the Cultural CSs.
It's also important to understand one thing: It doesn't matter how far away a CS is. All that matters is that the CSs become aware that you exist. Once they know you exist, they start issuing tasks that when you complete them gives you BIG chunks of Influence (25-50 points). The ONLY task they issue that requires that you have units nearby are the "A nearby barbarian camp is making us nervous" task. If you maintain a half-dozen or so units on patrol around the map, even those generally become doable. All of the other tasks can be successfully completed even if you and the CS in question are on opposite coasts. If you flesh out the Patronage tree, once a CS is your Friend, they will remain your Friend (or Ally) for a long, long time. Add just a little Piety, and having the same Religion will give you more and longer-lasting Influence.
About the only situations where beFriending CSs isn't overwhelmingly advantageous is in warmongering environments where civs start conquering CSs left and right. Because of the World Congress though, it's more advantageous to have a CS Ally than it is to have that CS as a member of your empire via conquest.