The key here is that it is pretty much always a longterm loss to not focus on growth. If you need to build a museum, you build it A LOT faster with a 30 pop city compared to a 15 pop city. This means that whenever you're not focusing on food, you should make sure whatever you're focusing on instead is actually worth the loss of longterm power. Focusing on production to get workers out? Are you working multiple unimproved tile? Absolutely, get right on it. Working unimproved tiles is terrible. Focusing on some cultural specialists to help you get policies faster and speed up your progression even more? Usually worth it. Focusing on production to get a production-building up and can produce other things faster? Usually worth it. Focusing on production to get a food-building (aqueduct, watermill, grocer, medical lab) up so you can grow faster? Pretty much always worth it. Here you run into some conflict, food-buildings are more important than production-buildings, but production-buildings help you get the food-buildings up faster, making them worth focusing on first. Everything besides this is low priority, or varying priority based on the situation. Can I cut unit-production to get 3 more pop or do I need to unit to keep aggressors away? Can I afford to use some scientists to gain short-term science at the cost of longterm science(growth), would it be better to focus production on a university? Do I need these banks to afford unit-upgrade or can I just trade off my last copies of a few luxuries? None of these are easy questions with straight up answers, if they were this wouldn't really be a very fun game. Civ5 is really a game of greed, how much greed can you get away with without getting punished? How much punishment can you survive? Is the risk worth it?