“If you persist instead of giving up, then comes the one moment at which there is a chance of going forward a little. And not only do you have the impression of going forward a little, but sometimes you suddenly have the impression — even if it is only an illusion — of a tremendous opening.”
Quoted in Master Artists: Giacometti by Yves Bonnefoy
It can, undoubtedly, be hard to keep at it. I don’t always, and sometimes when I do things go from bad to worse. I tend to persist for a bit (a “bit” being anywhere between 10 minutes and a few hours), then put it aside for another day. For a time when I’m able to think of something specific to do with it or willing to let go of what I’ve already done and be dramatic or willing to be more patient with it. Some of the paintings I’ve been most pleased with had frustrating starts. (The converse applies too.)
How do you keep at it? You just do, in the knowledge it’s a marathon not a sprint. The memory of those times when suddenly you know what a painting wants, or you inadvertently do it, provides the motivation when you’re struggling uphill. Persistence creates endurance; endurance enables persistence.