This sketchbook page by artist Leonardo da Vinci provides a great example of what a quality A Level Art sketchbook page should look like: overlapping, incomplete sketches, surrounding by evaluative handwritten notes.
Tips for Producing an Amazing GCSE or A Level Art Sketchbook
Ruth Beeley: St George's School, Hertfordshire England 2011. Sketchbook page for A Level Art Coursework final artwork, exploring the theme of war. Prisoners of war are depicted using biro pen on an ink and acrylic background.