If you were to travel to many of the tennis academies that are located in Florida, you would invariably hear a common theme when it comes to groundstrokes and serves. Coaches at these schools make certain that their charges develop consistent and appropriate stroke and serve finishes.
As in most things in tennis, there really is no one right way to stroke a forehand or backhand. Nor is there just one way to hit an effective first or second serve. For instance, some players hit a one handed backhand, while some players prefer the two handed variety. Some players hit their forehand using a full western grip. Others may use the Pete Sampras-like eastern forehand grip. Some of us like to crank up the big, flat first serve. Many of us are content to spin our first and second serves into the box. John McEnroe was a consummate serve/volley player. Andre Agassi has the big groundstroke game.
My point is simple. There are many "right" ways to play the game of tennis. However, if you want your strokes and serves to be more reliable, you need to focus on making your "finishes" more consistent.