I posted this in another thread that is down a few.
I've done this in all of my higher level games(emp/deity), I feel like if I don't get the GL, I get left way behind in tech, and must be a constant warmonger.
When I use the GL I always am a commercial civ. It's a nice head start on the alphabet>writing>lit>GL thing I like to do.
As soon as I found my capital I either build two warriors or two scouts (for scouting ), and then a spearman for defense and MP.
I set science to 20% writing. This 20% science allows me lots of extra money for the lux slider, and can therefore get the maximum despo production from my citizens. I then start work on a settler and move him to a nice location.
Now, depending on the land around me, I'll either try to make another settler factory, or start a palace pre-build for the GL.
I continue to expand and produce more cities, each starting with first a spearman and then a settler. (On sedentary barbs, otherwise I include a warrior escort)
Sooner or later I'll get literature, and then switch the palace up with the GL. I then take my science to 0%, no scientists, nothing. I depend entirely on my palace pre-build.
I never hoard techs; I freely trade them, might as well make friends and get some extra gold. Besides, AIs can never pre-build, so I almost always beat them to the GL. If I miss, there is always Ctrl-Shift-Q.
I will then ride the GL, go to monarchy, build up massive gold stores, make a bunch of friends, build the inner workings of my empire, and by Chivalry have some 30-so horsemen ready for upgrade. This is where those gold stores come in really handy. For 80 gold you can upgrade a horseman to knight. (40 if you managed to snag Leonardo's workshop.)
Those 30 knights can keep your weakest neighbor (but rich in resources and lux) occupied, while you continue to build up your military to an even higher level.
Hopefully you can get a good amount of luxury items and raw materials from your war, and then have some good bargaining materials for the rest of the world.
Sooner or later Education will come, and the GL will cease to be useful. The coffers come in handy here also. You can up science to 100%, even at a 60-100 GPT loss, without really killing yourself. As soon as you beat the AI to a tech, such as printing press, you can immediately trade it to the rest of the world, and start stripping the AI's monetary income. The AI will then have to slow his own tech pace, leaving you with at least a 3 to 4 turn slack.
The GPT deals will keep large rival civs off your back, because they won't, often , backstab you. ROPs come in handy too.
By cavalry you can start another war with a rich neighbor, and take over some more, if you feel like it.