Awareness of the out-breath accompanied by labelling of thoughts can be a valuable mindfulness practice, especially if you can set aside 15 minutes a day or more for the purpose. Sit still and notice the out-breath without trying to breathe in any special way. When thoughts come into your mind, just silently say 'thinking' and return to the breath. Pema Chödrön, in an article on the shambala.org website, suggests the following approach:
"The key thing here is, try not to watch the breath, but try feeling it go in and out, so you feel one with the breath. Just see if from the beginning you can minimize that sense of heavy-duty watching it, and just feel the breath going in and out."
"Then start to emphasize the outwardness and the space that the breath goes into, and emphasize that more and more. And then just see if you can let that sense of outwardness and space begin to pervade the whole practice more and more."
"... the other part of our meditation instruction is to label any thoughts we have as thinking and just let go of them and come back to the outbreath. That instruction encourages us to interrupt the constant barrage of talking to ourselves."
In doing this practice I am always amused at how my thoughts go off on adventures when I'm supposed to be maintaining awareness of breathing and at how effectively labelling them simply as "thinking" calls a halt - until the next time!
If you can't manage 15 minutes, start with five minutes and gradually work your way up.