It has been said that it takes 2 people to make a masterpiece - a talented artist and someone to shoot him/her when its finished - the gag illustrating one of the thorniest problems and most frequently asked questions; 'How do you decide when it is finished?'
Of course, personal taste and what effect you set out to achieve plays a big part in this crucial decision. Rather like cooking veggies, whether you like yours with a bit more crunch in them or tender, we can all agree there is an optimal range between raw and over-boiled which works best. While an expert chef has his greens 'just right', the amateur artist finds it all too easy to 'overcook' a painting.
Here is a great little video by American artist, Larry Seiler on developing sensitivity to each brushstroke and actually counting them for the purposes of the exercise.
Perhaps you'd like to join in Larry's challenge with a little alla prima still-life, and if so, why not post it as a reply to this thread - with your brushstroke 'score' of course! - and any comments about how useful or difficult you found it?