Sketchbook.
I had a little drawing training as a child, mostly because I was too afraid to say no to my mother. Very little of that training survived. I came back to sketching much later for a different reason that it makes me sit still, look longer, and practise patience.
Minimal sketch of mountains, a campfire, trees and birds
Ink sketch of a boat at sunset
Ink sketch of a steam train
Ink sketch of a torii gate and Japanese landscape
Ink sketch of an old gate beside a wooded path
Ink sketch of a ruined stone tower
Ink sketch of a stone building among rocks and trees
Perspective sketch of railway tracks

Turns out, patience can be practised one line at a time.