I find the practice of “noticing a thought and letting it go” a mental way of doing same. Noticing something I was about to go do and letting it go enables me to “re-capture” the mental and physical energy that I was about to go spend on that thought or action, and then either bask in it or repurpose it for something else. It’s all part of the endeavor of “not letting the energy escape“ or transmuting transient sparks of directed motivation into a purer abstract “energy”. This also is the point of the principle of “forbearance.” It’s not some sort of severe austerity, it’s about getting the energy you were about to spend back, and thereby “building energy.”