If you have a US startup called X and you don't have x.com, you should probably change your name.
The reason is not just that people can't find you. For companies with mobile apps, especially, having the right domain name is not as critical as it used to be for getting users.
The problem with not having the .com of your name is that it signals weakness. Unless you're so big that your reputation precedes you, a marginal domain suggests you're a marginal company.
"The best way to increase a startup's growth rate is to make the product so good people recommend it to their friends."
Do things that don't scale
One of the most common types of advice we give at Y Combinator is to do things that don't scale. A lot of would-be founders believe that startups either take off or don't. You build something, make it available, and if you've made a better mousetrap, people beat a path to your door as promised. Or they don't, in which case the market must not exist.
Actually startups take off because the founders make them take off. There may be a handful that just grew by themselves, but usually it takes some sort of push to get them going.
The 2nd counter intuitive point is that it's not that important to know a lot about startups. The way to succeed in a startup is not to be an expert on startups, but to be an expert on your users and the problem you're solving for them.
Mark Zuckerberg didn't succeed because he was an expert on startups. He succeeded despite being a complete noob at startups, because he understood his users really well.
If you don't know anything about, say, how to raise an angel round, don't feel bad on that account. That sort of thing you can learn when you need to.
Trust your instincts about people
One of the common mistakes young founders make is not to do that enough. They get involved with people who seem impressive, but about whom they feel some misgivings. When things blow up they say "I knew there was something off, but I ignored it because he seemed impressive".
If you're thinking about getting involved with someone—as a cofounder, employee, or investor—and you have misgivings, trust your gut.
If someone seems slippery, or a jerk, don't ignore it. Work with people you like, and you've known long enough to be sure.
How to decide who to hire
One of the best tricks I learned during our startup was a rule for deciding who to hire. Could you describe the person as an animal? It might be hard to translate that into another language, but I think everyone in the US knows what it means. It means someone who takes their work a little too seriously; someone who does what they do so well that they pass right through professional and cross over into obsessive.
Framing startup ideas
The initial idea is a starting point; not a blueprint, but a question. It might help if it was expressed that way.
Instead of saying your idea is to make a collaborative, web-based spreadsheet, say: can one make a collaborative, web-based spreadsheet?
A few grammar tweaks, and a woefully incomplete idea becomes a promising question to explore. Most startups end up nothing like the initial idea. In the process of discovering your idea is broken, you'll come up with your real idea.
A good rule of thumb is to stay upwind; to work on things that maximize your future options. The principle applies for adults too: stay upwind for as long as you can, then cash in the potential energy you've accumulated when you need to pay for kids.
One reason downwind jobs like churning out Java for a bank pay so well is that they are downwind. The market price is higher as it gives you fewer options for the future. A job that lets you work on exciting new stuff will pay less, as part of the compensation is in the form of the new skills you'll learn.
There is no magically difficult step that requires brilliance to solve.
You need 3 things to create a successful startup: start with good people, make something customers actually want, and spend as little money as possible. Most startups that fail do it because they fail at one of these. A startup that does all three will probably succeed.
And that's kind of exciting, when you think about it, because all 3 are doable. Hard, but doable. And since a startup that succeeds ordinarily makes its founders rich, that implies getting rich is doable too. Hard, but doable.