Plan to take breaks after thirty or forty-five minutes at most. Any longer and it is likely that nothing more will sink in. Take a short break in between sessions and have a glass of water or something similar to drink. Get up and walk around.
Plan revision in the evenings after school to allow for relaxation time.
Plan to revise specific topics in each subject, not everything at once – planning time provided.
Ensure that each session starts by tackling the most difficult bits first.
Revising with the TV or radio on or with loud music is not a good idea.
Plan to cover each subject several times and revisit each one near to the exams.
Have all the books you need to hand so you don’t have to go off looking for information.
Reading is not generally enough. Making brief notes in either words or pictures helps to remember.