Execution yields to brute force -- you stay up late, brew another pot of coffee, or send one more email -- but ideas are elusive. You can't just will them into being with hard work. Instead, you have to lure them out of hiding with tricks and finesse. 

That means there's a ton of advice out there on how to increase your odds of coming up with great ideas, from innovative brainstorming techniques to long walks to doing literally nothing (that last one comes from Einstein).

But according to a fascinating blog post by entrepreneur and former Y Combinator president Sam Altman, there's one key ingredient of an idea-friendly environment you're probably not thinking about enough: who's sharing it with you. 

Better company leads to better ideas. 

The company we keep has an outsize effect on what ideas we're willing to take seriously, Altman points out in the post. "The best ideas are fragile; most people don't even start talking about them at all because they sound silly," he writes. If you're around people who are hostile to the new and outlandish, you'll be even less likely to take your more unorthodox ideas out for a test drive. 

"You want to be around people who don't make you feel stupid for mentioning a bad idea, and who certainly never feel stupid for doing so themselves," Altman continues. 

But just surrounding yourself with people who won't laugh you out of the room for bouncing around an out-of-the-box idea isn't enough. If you really want to increase your chances of coming up with more ideas, you want to make sure your friends are curious, future-oriented types as well. "It's important to be in the right kind of environment, and around the right kind of people. You want to be around people who have a good feel for the future, will entertain improbable plans, are optimistic, are smart in a creative way, and have a very high idea flux. These sorts of people tend to think without the constraints most people have, not have a lot of filters, and not care too much what other people think," he says.  

The opposite is also true. If open, exploratory types are good incubators for ideas, closed and cynical folks are death to them. "Stay away from people who are world-weary and belittle your ambitions," Altman says, noting that "unfortunately, this is most of the world."

All of which isn't to say you should ditch your cautious childhood friend who tries to talk you out of anything even slightly risky or novel. But maybe don't discuss your latest ideas with him either. Instead, cultivate a group of other friends who welcome discussion of crazy possibilities and potential futures and make sure to find time to spend with them. You'll have fun, but you'll also probably have more and better ideas