One of the most important things your brain needs is sleep. Sleeping gives your brain the time and space to sort through what you've learned in the day, file away your memories and recover if you're ill. If your head is full of busy thoughts, write them down in a journal so you can forget about them until the morning. Getting thoughts out of your head and onto paper can help you feel calmer and take pressure off your brain. With a clear head you're more likely to have a good night's sleep.