We can all become so focused on a particular task that we ignore helpful and relevant information. This is why it is so helpful to take a step back from what you are doing and see if there is a different tactic that could be applied to the situation. Welcome the comments of outside observers who are not as mired in the work as you are. This will also assist with the gargantuan task of avoiding the tempting pitfalls of group think. 

In life, there are errors of commission and errors of omission. Notice what is not there but should be as much as you would pay attention to what is there and should not be. Ask questions to generate information that can better aid your decision-making process. Many times, people do not notice behavior in society and in the workplace. In particular, instances of immoral behavior are frequently intentionally and unintentionally ignored. Sometimes, it is easier to do and say nothing rather than blow a whistle. In addition, people can work very hard to prevent others from noticing their illicit actions.

Psychological tests have shown time and time again that it is possible to hide information from people by directing their attention elsewhere. Magicians are masters of this art. The term for people missing information that is right in front of them is "inattentional blindness." For example, this often happens when pedestrians are focused on their headphones or iPhones and not watching where they are walking.

The Power of Noticing: What the Best Leaders See by Max Bazerman, 2014

This is a superb read, unlike any other leadership books that I have read.

Books on leadership