1. Be very focused on your customers. Make sure that your company is solving a real problem that customers are willing to pay for.

2. Start small. Don't build up expenses or infrastructure before you need them. Using online services are ideal for startups.

3. Work with people you like. You're going to be spending a lot of (stressful!) time together so it might as well be fun.

Of course there is much more to consider when starting any sort of business--but, in my opinion, these are the top three things to keep in mind.