During my adventure of coaching people and trying to grow myself, I've stumbled upon one vital realisation. There is a subtle efficiency killer we all are ignoring.

This thing is what can be called scientism. In short,

the dogmatic endorsement of scientific methodology and the reduction of all knowledge to only that which is measured or confirmatory.

How does it manifests itself in our day-to-day life?

Many people do not take actions if they are not sure that the mental model they've learned is "scientifically correct" or "proven to be scientific".
I think, scientism + perfectionism is a deadly combo. 

The trick with mental models is that they are not 100% correct by definition. Models approximate our understanding of concepts and they have different probability of being applicable. 

So, ask yourself these questions:

1.  Is it better to get some results almost immediately and move your progress 10% or is it better to waste your effort trying to find "the magic bullet" to make a "quantum leap" up to 80% of progress?

2. Do you know enough scientific methodologies to be able to assess the papers, experiments and interpretations in various branches of science like psychology, sociology, science of expertise and so on? 

3. Do you really need the best possible result? Is it your calling? Will it give more meaning? How are you sure about that if you do not run small experiments?

Being pragmatic and open for new possibilities is quite liberating. 

So start running small experiments with what you already know and apply new mental models as soon as you find something better.