I'm a A/A* targeted student, and recently I have adopted the Pomodoro Technique and guys you really need to try it out. Research shows that our attention span drops dramatically after 30mins, so this technique is really good for boosting your grades. Before I started, I wasted probably hours every day procrastinating during my revision after getting bored. The technique is a fancy way of saying "take breaks" but I find it useful because it makes you work hard as you know you have a break coming up, and it seriously boosts productivity. For example, today I have studied:
50 mins of Geography.
25mins of religion.
50 mins of Chemistry.
25 mins of Music.
50 mins of Maths.
50 mins of German.
25 mins of English.
25 mins of Physics.
25 mins of Latin.
25 mins of History.
The technique is basically:
25 mins work
5 mins rest
25 mins work
5 mins rest
25 mins work
5 mins rest
25 mins work
20 mins rest
Repeat.