Hello,
All over the internet you can read or watch various videos on “fitness gurus” who advocate a certain way to perform an exercise movement. My question is, is there an optimal way to perform an exercise? I’m reffering largely to the main barbell movements ie. squat, deadlift, bench press, and press. But, also ancillary excises that run the gamut from curls to reverse hyper extensions and everything in between. Also, what resources either books, videos, articles, etc would you recommend to teach the proper execution of an exercise?
I hope what I am asking makes sense. Thanks! 
In order to answer your question, we’d need to define optimal.
There are many styles and strategies that people use to complete a given movement. As to whether one style and strategy is better (or worse) than another depends on the outcome we’re looking at, e.g. health, injury risk reduction, performance, etc.
Short answer, I think there are more and less efficient ways to move from a performance standpoint. For the other outcomes, meh…I think most people hold their opinions too confidently.
What if we are trying to accomplish all three of those criteria, health, injury risk reduction, and performance. Is there then an “optimal” way to perform for example the squat?
There may be more or less effective ways for an individual to move in order to accomplish a specific task/goal, but no, there is not an “optimal” way that generalizes across the population.