Important decisions carry risk and can unnerve and distract us.
One instinct is to delay, merely because doing something risky and distracting later is better than doing it now. That's the wrong strategy.
You should decide the moment that new information relevant to the decision is more expensive to obtain than the cost, the inaction and the anxiety of waiting.
So, don't apply to 30 colleges and see which ones you get into before you decide. That'll cost you thousands of dollars and take up months of your life.
Don't delay hiring a great CMO merely because it's entirely possible that other resumes might appear one day. Your hesitation might cost you the person you've found, and going three more months without a great person on board is way more expensive than waiting for Ms. Perfect.
Make high leverage decisions early, and profit from your ability to take advantage of commitments when others are still in limbo.