You don't build stuff like this just because it looks cool.
There is no instance of a nation benefiting from prolonged warfare.
It's tempting to get ahead of ourselves. It's why folks rack up debt.
In the context of StarCraft 2, though, you may begin to think that what you're doing in the process of learning macro skills is boring. You see live casts and replays of pro gamers, seeing the builds they use very effectively. You want to do the same, because they win and because it's more interesting than what you need to do to build fundamental skills.
Stop that.
I humbly refer you back to these two entries in which I talk about what you should be building and how often you should be spending your resources. If you do this, over and over again until at least a couple promotions have gone by, you'll be laying a stronger foundation for pulling off those daring gambits you see the pros execute. If you focus instead on some other strategy, you may get past Bronze or even Silver, but the higher ranks are going to be more of a frustration. Experienced players are already well-prepared for your cheese.
So you're building basic units, builders and the means to keep building both. What do you do with them, though? Should they stand around your base protecting your pretty buildings? It can be an effective defense, sure, and if you want to play that way, go for it.
In my humble opinion, however, the quickest way to end the fight is through direct, uncompromised aggression.
As long as your production buildings are humming along and churning out more units, there's no reason not to send the bulk of the units you've already built up your opponent's ramp. Especially in, say, the first six minutes of the game. Before they can reasonably get any sort of high-tech response mounted, you should make them spend their resources on replacing whatever you manage to destroy. You can't do that staying at home.
Now, I'm not saying you should follow every move your units make. At low levels, micro-management isn't nearly as important as macro skills. But if your forces manage to past their defenses, there's no reason not to direct them to the mineral line. Be it in their starting base or an expansion, blasting workers slows down their economy and is annoying as hell. While they recover their lost time and units, you're building away for an even bigger assault.
Worried they'll do the same? You should be. But if you're building as much as you should, constantly producing units and ensuring you have enough food for everybody, the assaults your opponent mount in response should not do a great deal of damage. You might lose a few units but you have more on the way.
If your opponent gets behind you with air units or some sort of stealth attack, chances are you haven't been attacking enough. It takes time to get air units, time you could be spending sending ever-growing waves of basic infantry against them to distract, harass, inhibit and destroy.
Sure, you'll play the occasional hour-long macro game, with top-tier units slugging it out while you trade bases. But you learn little from such experiences. Quick wins, and quick losses as well, teach us a lot more about the strengths and weaknesses in our styles of play. Learn these lessons well, refine your style as much as possible, and just keep building and attacking.
It's the advice I've gotten and am trying to follow. I'm sure it'll get me out of Bronze league.
Someday. Hopefully before Heart of the Swarm gets here.