Spent the afternoon at the range testing some .308 reloads with the old M1A. Pro

Spent the afternoon at the range testing some .308 reloads with the old M1A. Problem wasn't accuracy, it was the trigger finger. When in service, they'd say a clean trigger pull is like squeezing a lemon, not yanking a rope. Still true today. What are your go-to tips for mastering that smooth squeeze?