If You Want to Succeed, Hate Your Ideas.

Ok, so hate is a strong word. You should love your ideas like they're your children.  But you should be skeptical of your ideas. Even your best ones. All of them. No matter how great they sound.
The best thing you can learn is how to pull the rug out from under yourself.
Be unforgiving. Find your weaknesses. Because if you don't, you competitor will. Along the line a sharp investor surely will.
I love ideating. Eureka'ing is so much fun, and is the gateway to the entrepreneurial process. Granted, it's much like writing: the best ideas come when you least expect it.  So whenever you have a great idea, write it down.  And then start tearing it down.  It is a cathartic and important exercise. If you don't rattle the gates early, often, and thoroughly those gates won't withstand the maelstrom they are going to face down the line.
Do your due diligence from the get-go. It will save you a lot of time, effort and money.
Here's my approach:

• Google it. Now. 
• Great ideas are a dime a dozen. Execution is everything. Sure. But your great idea is probably taken. Go find out. Now. If some other company is already doing it then keep looking. They will have competition. If your idea is different you need to find out how, and fast. No easier way to find out than by learning about your competitors early and exploiting their shortcomings.
• Find the Holes
• If you've got competition, you should be finding out how to fill the holes they have in their business model and how to exploit them. If you're extremely lucky and it's an open space start identifying your weaknesses (I doubt it. Keep looking.). I'll say it again: The best thing you can do is learn how to pull the rug out from under yourself.
• The Idiot Test
• If you can't explain your idea simply now, you won't be able to communicate it effectively ever. You don't need a glossy, perfect elevator pitch. But if you can't get your idea across in a few sentences to a layman, how do you expect to amass millions of devoted customers? Try it on your grandmother, your kids, the mailman. Anyone. If they stare blankly-and they will-you need to keep working.

So be suspicious of your good ideas. You'll filter out the so-so ideas quickly and the result will be the very best ideas in your arsenal--and the start of a pretty decent business plan.