Keep computers and TVs out of the bedroom, and switch phones off at bedtime. Playing games and chatting online eats into sleep time, making it hard to function the next day.
Try to get up at the same time, even at the weekends. Keeping wake-up times on school days and weekends to within two hours of each other helps establish a regular rhythm.
Let the sunshine in! Sunshine helps switch off melatonin, the hormone that helps sleep.