Yogi: I experience pressure and discomfort in the head whenever I notice the in-breath and out-breath.
Sayadaw: Don’t focus too much whenever you’re aware or there’ll be tension in the head because you use a lot of energy.
Paying attention is directing attention to the object, not pressing onto the object. Placing the attention onto the object, that’s enough.
Yogis use too much energy to be aware; that’s why tension builds up.
If the mind becomes tense whenever you use a particular object (e.g. in-breath and out-breath), it’s better to switch to another object because old habits are hard to change.