Animal Crossing New Leaf megathread: The economy of Bells, Fruit and Turnips.

Turnips are the only way to really make the big bells. If you get a full cupboard of them(~1.8million bells) on a really good week you can get upwards of 10million back. Of course, fruit trees with non-native fruit are helpful to get started too. Going to the island and beetle hunting in the evening also works pretty well.

As for upgrading shops, just keep buying things. The only real roadblock is the last upgrade where you have to rely on a random event to occur 4 times before you can, which took me forever to occur.

Though I will say, if you're playing animal crossing for hours a day, you probably are going to get burnt out on it. There isn't really anything major you can do to the process up (and that's by design).

I figured turnips were an important, but I never wake up early enough to catch the turnip seller =\ my entire town is almost completely non-native fruit (to the point where I almost forgot my native fruit was cherries). Nah, I'm not playing hours everyday, just one hour or so max, but I do spend a lot of that time decorating...