From a pedagogical point of view: personality preventing productive piano practicing is preposterous - before the after - and utterly undesired.
Therefore I advise the following (as it is a “path dependent” process): first practice with focus and purpose, and only then give sway to the weakness of spirit and flesh.
See: 182 • Disciplina
The pianist inhaled expressively at the first note and did not exhale until the last; the music turned blue and eventually fainted.
"When the piano likes me, I touch it. When it doesn't, I don't."
The young pianist played like Lord Nelson's frigate captain, who was so enthusiastic about the fleet going to war with the Spanish Armada that he started firing his cannons still anchored at the harbor. Too soon too loud!