You bring up a good point at the end there, Sofia — about using mindfulness to measure as perhaps counter to the spirit of mindfulness. I guess my response would be this: you should be mindful and nonjudgmental for some portion each day. You should just sit and watch what your mind is doing. When you go back to focusing on your work or other things, you can recall your experience while you were being mindful, and just note whether you were feeling better or worse than normal.
If you tend to struggle with anxiety or worry, you can be mindful of those creeping feelings of worry during a mindfulness session — you can note them, as many mindfulness exercises recommend. Then you can take a few minutes afterward, and ask if you had more and worse feelings like that than you use to. Progress is made when the destructive and detrimental thoughts and feelings are becoming either weaker, less frequent, or both.
And this actually can be helpful to make you more mindful, because when you’re not being bombarded so much by unwholesome feelings and thoughts, you can tend to be more mindful and present in daily life.