To my mind the 4 strong civ abilities all have a long term approach
Commercial : reduced corruption helps a big empire. Big empires always win. (by big I mean haveing many tiles worked on by population ). If I have a bigger ecomony than you I can outmatch you in whatever field you wish to compete. I can research faster, or be rich and buy friends, or pump out and maintain a bigger military.
Scientific. The free advance can either boost you up to access to a new wonder ahead of the opposition so you get a building headstart, or be sold for favours. Shames its random.
Cheap science buildings can help a lot to get the libraries but after that you should be big enough to build city improvements at a decent pace anyway. Can help an ancinet military agressive stragety as you already have bronze working and can research iron quicky to get swordsman early. (NB Greeks get hoplite straight out of the box , and Persians get immortals unnervingly early if they mean it ).
Industrious. Extra city shields is a nice little boost in ancient times but really we are talking about the workers here. This is powerful and stays that way through out the game. Masonry gives you a shot a pyrimids staight away.... free granary is VERy handy, also might trigger your golden age early without a draining war.
Religious - Nice early boost as you can get temples early. This is a good approach for large cities and empite and goes well with commercial for a peacful cultural / economic approach. Also you get a head start towards monarchy with ceremonial burial.
Vaery powerful in the mid / late game is you go aggressive as the Democracy / communism instant government switch gives you a peacetime wartime economic gearshift.
The weaker ones :
Expansionist.
Its a gamble. You can get a flying start, but it can all dissapear very early. Your flying start has got to give you enough momentum to stay the rest of the game as your advantage is worth nothing once you have explored your local landmass. hint : switch barbarians off, and have pangea continent, preferably on a n emptier than average map.
Suggested tweaks (any or all of ) : Settlers and scouts need no maintainance. Settlers cost less shields. City centre produces more food. get 2 scouts. scouts have defence of ADM 012, so they get to survive an attack and withdraw.
Military. 1. Barracks are cheap anyway, once beyond ancient times who cares. 2. Promotions..... to get enough fron this ability your ancient times approach must go something like this :
found an early city or three with big production from 3-4 tiles. Build barracks, build strongest military units available. These cities do not participate in the expnasion of your civ in any other way. No wonders , no settlers , no culture , not too big a population. Find oppents, attack oppenents, get leader , make army attack opponents, build heroic epic (probably in one of the production heavy cities). Keep attacking opponent (its hard to keep it up by this time unless you are winning the war, you might be onto your second oppenent by now ). Get more leaders , hurry wonders big time. Then you settle down with a lot of territory and a fistful of wonders and buld a regular economy. It help if you can find a neigbor to have the occasional border dispute with to make more leaders without any real drain, but you have to trust them to want peace when you've had enough.
It's all a bit risky really. If you pick on the wrong gorilla early then they either criplle you for all eternity, or you grind out a stalemate and wish you had another civ advantage instead. If you're going to do this I recomment the a civ which gets a good unique unti early in ancient times. Persians are one tech advance from the immortals !
suggested tweaks (any or all of ) . Cities can support more units without costs in early governments. Less war weariness in democracies and republics (every citizen's a samurai so they approve of your wars... right ? )
Just my thoughts.....