I play on normal speed at the beginning of the game and switch to 2X speed once the dam is built. That cuts the waiting period for the first crop, and the interval between crops, by half. I play on normal at first because the villagers eat less food. That allows me to build up food stocks, and then, when I get over about 500, I'll take the farmer away and put him or her on research or (if I've got that far) building the dam. Of course, if the food levels drop below 300-200 I'll put the farmer back. Usually, however, I can last out at around the 500 mark, topping up the food with mushrooms, until the dam is finished.

I don't allow any babies until the after the dam is built either. This is because I need as many villagers working as possible. Again, switching from normal speed once the dam is built leaves the mother "only" looking after her baby for two instead of four hours.