He also indulged in theatrical scenery, which I would think is good training because of the scale. The school at the time had limited use, for basically student moved around a large room with statues and busts, drawing them from multiple angles. Observed at Farley Hall Turner would start not just one but a group of watercolours using the same materials and colour in all paintings. At Petworth House also Turner was observed working on several oil paintings going from one to the other. This is good commercial practice as sometimes working on dry paint rather than a wet into wet is required.
Oil paint takes days rather than hours to dry.
Turner's early watercolours were drafted in detailed pencil drawings, had graduated washes of colour on white size. A ruler was often used on architectural details. Progressing from here Turner used the pen and pencil loosely and less detailed as he got older. Using a number two or three h pencil for the distance and a number two or four black softer for the foreground. Turner would scratch out details with his sharpened thumbnail or the end of a brush, stipple over this with dry brush technique, or remove colour with blotting paper after immersing the whole watercolour in a bucket of water.