Think. Act

You should think before you act. This is sound advice that shouldn't have to be said... Sadly, one should never underestimate the power of an idiot's ability to amaze.

The part that is never said is:

Think before acting until correct action becomes second nature... When in doubt; think!

Still, the biggest mistake of thinking is when you do so in a vacuum. Get advice! Find someone who's been there before. Filter advice through metrics by weighing the success of the adviser with their age and how it stacks against the advice a group of his/her peers.

Oh, don't ask Facebook, Twitter or any other social media for advise.