I think most people have one top idea in their mind at any given time. That's the idea their thoughts will drift toward when they're allowed to drift freely. And this idea will thus tend to get all the benefit of that type of thinking, while others are starved of it. Which means it's a disaster to let the wrong idea become the top one in your mind.

I suspect a lot of people aren't sure what's the top idea in their mind at any given time. I'm often mistaken about it. I tend to think it's the idea I'd want to be the top one, rather than the one that is. But it's easy to figure this out: just take a shower. What topic do your thoughts keep returning to? If it's not what you want to be thinking about, you may want to change something.

I have found that my best ideas come when I'm taking a shower, when my mind is left to wander. My thoughts will drift to the idea that is at the top of my mind and I will have a moment of clarity.

The shower is when I come up with the most elegant solution to a problem that I've been struggling with. In the shower I figure out the best algorithms, the simplest way to store data, the best way to write an email I've been avoiding, the best tactic to negotiate something.

The interesting thing about ideas I have in the shower is that they are like dreams: I tend to forget them quickly. Sometimes I jump out of the shower to sketch something. I've been using the Voice Memos application on my iPhone a lot. When something comes to mind, I just start dictating into my phone so I don't forget it.

These days people seem to be addicted to information. We can't stop reading, watching TV, looking at photos, connecting with friends. But it's still important to have times when you just clear your mind and let it drift.

This is especially important when starting a company. There is no shortage of things to do or think about. But if you don't sometimes stop, take deep breaths, and let your mind wander, you might find yourself missing the big picture, over engineering simple problems, or generally hitting walls in your thinking.

Here's what I've found helps to have these moments of clarity:

1. Great ideas come in the shower. Make sure you bathe often :)
2. Get plenty of sleep. Great ideas might not come while you're sleeping, but you will wake up refreshed with a clear mind
3. Walk a lot. I find the slow pace of walking is great for thinking
4. Go to the gym. Particularly when I'm on the treadmill or elliptical machine for 30 minutes, my mind gets bored and wanders. Great ideas surface when this happens