The late Spencer Tracy was one of the greatest film actors of all time. He was nominated as best actor nine times and won twice. He was renown for his natural style and versatility. And he did not subscribe to any nonsense about acting. Once at a party he attended, several actors were discussing the merits of Method Acting. After a long and often heated discussion that Tracy only observed and did not take part in, one of the actors asked, "What do you think, Spence?" Tracy replied simply, " I think it is very important for an actor to learn his lines." Simple and direct. An honest reply without any nonsense about acting. A reply I admire and applaud.
Recently an actor wrote to me and asked me to evaluate a video audition he had made. In it, he often looked down at his script before saying his line. I replied that he was too tied to the script to be effective in the scene. As an actor you have to respond to your scene partner, not to the book. So you have to free yourself from the book in order to concentrate on your scene partner. The book and not having the lines down also presented a barrier between the actor and his scene partner. I noted that his emotional responses were not reaching the audience and that he needed more intensity.
Now, here I have to tip my hat to the Method actors. The thing that made Method acting popular was how intense the actors who used it were. Marlon Brando, James Dean, Montgonery Clift, Robert DeNiro, and Al Pacino give us highly intense acting. Jack Nicholson does them all one better as he not only has great intensity, but he also is having great fun playing the role. This gives him the highest charisma that an actor can achieve. An actor needs to catch the casting director's attention with the intensity and fun he communicates while playing the role.
That intensity and fun is communicated to the casting director when the actor feels those qualities while reading for the part. I have always said that acting must be fun and it is very important for the actor to communicate that he is having a ball doing the audition or playing the role. Then the actor must also feel the intensity of the emotions his character is expressing. The actor does this by allowing himself to fully release his emotions without inhibitions. When he does that, the intensity takes care of itself. Remember that acting is not an intellectual activity, it is an emotional one. Make sure you are always emotionally in the moment before each scene begins. Then you need to respond not with words from the script, but with the emotions those words represent.