Just won a Prince game with Indonesia and was pleasantly surprised. Got my first spice city up early but focused on building up my mainland forces. When Kris Swordsman became available, I did the unthinkable... and traded an extra lux for the spare iron from a civ I WASN'T going to war with
That let me build a lot of extra kris swordsmen, who by and large got positive upgrades as I started a couple early wars and then ended them as soon as the other guy was willing to cede a few cities. In the end the Celts were wiped out (by the Spanish, with my help) and Rome was pushed from being third place to around fifth (Standard-size map)
With a little breathing room, I teched up, comfortably developing my cities with the money my luxes were bringing in and way above the happiness line. Kept all my good Kris swordsmen, disbanded any that had bad upgrades and were no longer needed. Took that time to grab caravels and establish cities on the other continents, getting my other spices. With so much happiness and money coming from my luxes, luxes I traded for, and the 'resource diversity' bonus, it wasn't hard for me to keep buying stuff as I needed it. I also lucked out and found Mt. Sinai early, and used it to grab the +4 Faith for Natural Wonders belief, and then when my religion was founded, I also grabbed Pagodas, Tithe, and Jesuit Education, meaning I had huge faith and happiness that I could then turn around into educational buildings. My culture exploded, and by the time I had to go to war again (against Attilla) I out-teched him quite a bit - and joining the war against him made me friends with the other front-runner, Spain. Their help got everything I wanted passed through World Congress since we were the two biggest voting blocks. Before long I was influential with everyone but Rome, who had a different ideology (the rest of us went Order, he was Autocratic)
So I took my high-tech armies and crushed him. He hadn't grown much since I slapped him around the first time, and with him eliminated from the game, I was the cultural victor at around 400 turns in.