I prefer resources rare and concentrated. This encourages warfare and trade which generally creates an intense game.
If every civ has every resource then what's the point?
My general principles in resource placement:
- I never put in more of one resource than the number of civs I plan to use.
- The number of civs decreases towards the end. Thus the later a resource appears the fewer there should be of it.
- I usually create two or three source locations for a single resource type to ensure there's an alternative supply and to force a civ to do some conquering if it wants a monopoly.
For example, in a game of 8 civs I might have 8 horses divided into three groups: 3 + 3 + 2, e.g. placed so that 2 civs will probably get 3 horse resources each, 1 civ gets two, and the rest none. Then I might have 7 iron also divided into three groups (3 + 2 + 2), but in different locations than where I put the horses. Thus if civs want to build knights they have to buy the missing resource (like swapping iron for horses) or conquer their neighbor.