Chieftain to Warlord

[SkyProf5]

Chieftain: start with 50 coin and 1st gen Barracks have no support cost.
Warlord: start with 0 coin and 1st gen Barracks cost 1 coin/turn.

Because of this you should (I think):
1. hold-off on on building Barracks until cities have started to grow (size 5 or 6?)
2. push your Science (0.0.10)
3. It might be a good idea to use your first Settler to Build Road next to your city square before founding the city. (to accelerate Science or support a Barracks)

A couple of reasons I think you can get away with this:
a. Barbarians are still at 50% combat effectiveness at Warlord. (25% at Chieftain)
b. Your Civ Advances still come faster than the AI's.

Good ideas for any difficulty level:
I. Found new cities as fast as you can. A new city should build: Military, Settlers, Settlers (or something close to that). The 1st Settlers built should go found another city. The 2nd can develop tiles around its city.
II. Once you start to have maintenance costs, set you Tax Rate to always keep your Treasury growing; even if its only 1 coin per turn.

 

[Whelkman]

On Warlord you only get up to five "free contents" so I wouldn't recommend growing past there. Personally, I'd target level 4 since more cities also generates unhappiness.

Regarding Settlers, I'm a hard believer in that one should generate landforms until he receives two. Because this Settler consumes more resources, it should never found a city and be strictly used for infrastructure enhancement.

Of course, receiving two Settlers means you have multiple neighbors so you'll need to execute battle plans quickly. Get those Chariots ready!