What learning habits can you suggest?

Our profession often requires deep learning; sitting down and reading, and understanding. I'm currently undergoing an exam period, and I'm looking for ways to learn more effectively.

I'm not asking about what to learn, or whether to prefer blogs over books, etc. My question is much more physical than that -

What do you do when need to study, and I mean study hard?

I'm looking for answers such as

• I slice my time to 2.5 hours intervals and make a break between them, but never during.
• I keep a jar of water nearby.
• I wake up at 6 o'clock sharp and start my day with a session at the gym.

What good learning habits did acquire, or wish you had acquired?

(I know this isn't strictly programming related, but it is programmers related)

I find the best way to set yourself up for learning is:

• Get plenty of exercise and rest
• Eat a balanced diet with little sugar and caffeine
• Try to find a quiet area conducive to concentration
• Try to practice what you learn from a book - theory is ok, but practice embeds the knowledge.