I've noticed that at about 10 minutes into the game I start accumulating more gold than I can spend. I play Orc and I know that while teching isn't forbidden, it is typically reserved for specialized scenarios. Also, I notice that in professional games they hardly ever go into low upkeep so I tend to want to stay below a size 50 army. I play at around 50% so I'm by no means spectacular at this game, but I don't suck horribly either, and I'd like to keep on improving. What should I be doing to prevent this obvious waste of economy?