Doing something intentionally is being present, being mindful and being in the moment. Intentional actions are not by routine, rote or unconsciously, as defined, things are done on purpose.
Do I think it is possible to ingrain this practise into your life that it feels like it is habitual? Yes, and if you are routinely being, and feeling grateful what an amazing gift you are giving yourself and your life.
In this e-book I talk about how being grateful in advance or intentionally grateful has become part of my manifesting practise!