Always discussing Easy/Hard concept of pitching with son, ie throw hard...easy. To trust the sequence and the kinetic chain and let the ball explode without feeling like your working to make it happen. For him it comes down to loading correctly, proper sequence and mechanics and pulling throughout the arm spiral after flip up. The validation is in constantly monitoring bullpens with radar and an emphasis on feel so he knows what he did when it produces results.
When he reaches new max velos while hitting his spots and tells me he felt like he was giving 80% effort, that's when he buys in.
Others really embrace the whole moving fast down the mound and throwing with max effort, but I watch it and it just looks awkward and unsustainable to me, heck if it works for them, who am I to say it's not a good approach. But I do often see scouting reports and hear baseball guys mention how easy and relaxed a pitcher creates velocity as if that is the desired trait.
I do think pitchers without the long levers need to use more effort through moving quicker to create and transfer more energy and can do so with more margin for error, than a lanky pitcher.