When I want to paint but don't know what to paint....
I tend to return to the subject I first started with, before I called myself an artist. I painted some apples fairly rapidly in watercolour then drew in pencil over them, and dared to frame my own work and hang it on our wall at home. The first paintings I ever submitted for a public exhibition were of fruit too. Nowadays I mostly paint portraits, but I do sometimes want a less challenging subject, something I can get on with without all the faff of preparation. That's when I sketch apples, oranges, pomegranates, most recently in oil pastels. I call this "comfort painting".