[lanamo]

whenever you transition from one activity to another, be aware of what you are doing in exactly this moment. that’s it.

[yrui]

This is mindfulness by definition, and also the answer to the question "how do you sustain mindfulness throughout the day?"

One purpose of having periods of formal meditation is to be able to sustain greater periods of mindfulness throughout the day. Formal meditation gets the mind used to coming back to what's at hand.

To take it a little further, you can practice having a tiny moment of mindful awareness each time before you open your mouth to speak or eat, and each time before you move your body.