The following tips come from the founder of Meet Up, a media site used by local groups to communicate.

He suggests asking yourself what kind of problem are you an answer to, as a company.  This will keep you focused, instead of starting projects all over the map.

Groups that he never imagined using his technology began to crop up once he put it out there for people to use, so he suggests being ready for the unexpected.  Even President Obama used the Meet Up technology to run various aspect of his campaign.  They had never seen their technology being utilized for religion or politics but there it was.

He also suggests that you do work that interests you, this will provide for a sustaining energy that you will need to keep your project a float.  Create what you want to be a part of, not what you think will make you money only.  This may mean going to work for a start up instead of starting one of your own, if they are already doing what you want to do.

Be a part of your project, not just the manager.  He suggests that you be a part of the building process, as he was when he was starting Meet Up.  He says that it would be a mistake to not know your product from the inside out; building it is one obvious way to gain this knowledge.

Lastly, you can’t do all this by yourself.  After doing some brainstorming by himself, he then went out and gathered people around him to help him focus, and then implement his brainstorming efforts.  Get people that you know, and people that are going to be passionate about what you want to accomplish.  You have to be able to trust them with your project, not only trusting their talent, but their want to get to the same ends as you.  Think of your team as a group of co-workers, not a group of people with delegation suggestions.  When you ask them questions, when they provide an answer, they should be part of that answer, and want to be, not suggests that you go elsewhere for what you are looking for.
In all, if you are a part of what you love, and have yourself surrounded by people that want to be as passionate and involved as you are, then your start up is that much more likely to succeed.