How would you describe what you are experiencing to someone else?
What words would you use to describe your headache, back pain, arthritis or depression? Using these same words in the set up statement in EFT can be invaluable to dissolving the cause of the ailment. For example if you use the word claustrophobic to describe a headache, it may lead you to a formative experience where you felt claustrophobic and so on.
Usually we describe what is going on in our lives when we do this exercise.
So describe how you are feeling to someone else (or to yourself, writing this down may be better) and use those adjectives/words in your EFT set up and rounds.