When is it finished?
When its finished you just know, but its impossible to put a time on it. I am fortunate that mainly I am not under time constraints to produce work. If I feel I am losing my connection, I will leave the work and keep coming back until the spark returns. I am guilty of overworking a painting, and then having to spend hours trying to get it back to where I started! This is where not being afraid to paint over your mistakes comes into its own!