Think of what your character might be feeling and find your personal memory that fits well with your character’s experience.
Bring out internal emotional memories and allow them to surface as your current emotion. In other words, think of something sad, become sad, show sad.
Your affective memory needs to be exercised, so practice bringing up these memories and emotions often.
Research as much as you can about the character you are playing. The more you know your character, the more you can find things about yourself to relate to your character.
Understand that method acting is the process of using emotional memory to bring out emotions for a character. It is not devoting your everyday life to a character.
Practice until it’s so ingrained in you, you don’t have to think about it. It’s not something you can learn overnight, but it will enhance your acting immensely.
Develop your emotional or affective memory by trying to think of memories from your past that move you in a certain way, and feeling those past emotions in the present.
Commit to the emotion you feel, and don’t try to use exterior symbols to portray it. Let the internal emotion take over the external emotion.