Leave a little space
A day does not need to be filled to be worthwhile. I like keeping a small stretch of the afternoon without a plan: a chance to finish a cup of tea, read a few pages, or watch the light move across the room.
Take the familiar walk
The same route can feel different every week. A new leaf, a changed window display, or a quieter corner is enough to make a familiar walk interesting. I try to leave the headphones at home once in a while.