Just sitting and reading the book is the WORST study method possible. Take it from someone who procrastinated for over a year trying to get her written exam done
Don't know about the UK but I found a reasonably priced app for my phone and set it up for quick bursts of 10 random questions at a time. Eventually it builds up a profile of the ones you are getting wrong.
I made index cards with the key points on (especially for stuff like Air law which is just a "memorise the info" game, no logic!) .
I carried these in my bag to read on my commute and would sticky tack them around my monitor at work so that when i got bored, my eyes would wander to them.
Hope this helps