I went along this week to an open painting afternoon with other artists where you bring your own art material and paint what you want . I realized once there I had forgotten in my stash to bring some pencils and I wanted to paint that girl  from a reference photo.Well I thought instead of asking for a pencil I would challenge myself to draw with the paint. It was a liberating experience as I realized you can easily erase your line if you keep your paint very watery and faint. The other advantage is a gain of time!  I managed to do the whole painting in one session!