Personaly if I'm going the fishing route I choose a civ that starts with it and play the lottery game in hopes I land on the coast with some fish, whales, or clams, but when I do this I also play water based maps as I get a head start that way. Otherwise I find the time it takes to research fishing sacrafices relgions for it hitting you harder in the long run, but I guess in some senario's if your starting spot was really really good you could do very well. The best part of the fishing stragey is the worker boat does not take up food while being constructed which makes for fast city production.