The “Frank Sinatra” mitzvah is the one that you say, “I’ll do it my way”. It is of the utmost importance for every person to follow Torah’s directions exactly.
King Shaul was a great man, however he did not complete Hashem’s request to kill off Amalek completely. Look at what happened to him. He was dethroned and led a miserable life. Was it worth it?
Most Jews will do many mitzvos correctly, however there is usually one mitzvah that each person says “Hey! Wait a minute, everything else I’ll go along with, but this one “I’ll do it my way”. What is your Frank Sinatra of Mitzvos? Lashon Hora? Kosher food? Driving in a car on Shabbos? Whatever it is, tell the truth to yourself, and then begin to modify your behavior a little bit at a time.
Hashem will take notice of your outstanding behavior and respond positively to your actions.