Spinning off what Rocketto asked earlier, but with a broader view.

Is upgrading your first priority for your ingots?
When you do upgrade, what do you focus on--coins, XP, or time?
How far do you upgrade your factories? <--Rocketto's question

Interested to hear your opinions.

Just a note: I am NOT asking what I should do in my town. Instead, I am asking what YOU do in YOUR town. If I especially like some of your strategies, I may "steal" them.

Also, if possible, give your reasons for what you do, so that knowledge may be furthered for all. Thank you!