I actually write ALL my ideas down! I probably have a hundred by now. But you are right, there's always one or two ideas that keep nagging at me, and right now I'm pursuing an idea that although it wasn't mine, right now I simply cannot not put it aside.

My filter for writing it down is simply if an idea represents an actual problem that a real person is facing. In other words, I don't write down an idea that I simply think it's cool, but when I hear about someone facing a real problem.

- Start with more than one business idea

- Identify an unmet business, social or consumer need

- Why the need was not already being met?

- Can you assemble the competencies to solve the need?

- Can you get the resources to bring the product/service to the market?

Disclaimer: Those are my notes from a great presentation by Antony Awaida: http://www.startleap.com/

1) Collect your ideas.

2) Ask: "which one addresses the most user pain?"

3) Do that one.

4) Put the leftover ideas in a "maybe later" pile.

5) To maintain focus, any new ideas that come along should also go into the "maybe later" pile.

6) Profit! ;)

Never write an idea down. The ones that are worth pursuing are the ones that keep nagging at you long after you've moved on to other things.

Writing my ideas down helps them stop nagging me, allowing me to focus on what I rationally think is the most viable.

You don't think this is the right approach?

I write them down and only a few keep nagging me. The others are frequently good ideas I'm just not excited enough about.

very bad advice. you must write down every idea dated, witnessed and signed. for i.p. issues. And they say, the witnesses must not be related to you. (!)

I don't think you can tell for sure until it succeeds. It's like the halting problem.