Get some exercise during the day; morning, afternoon or early evening are best. Not just before you go to bed.

Morning sun is the best for our brain. 

Try allotting a specific "worry time", at least a few hours before bedtime. Get unresolved worries in check. In order to resolve worries, it often helps to write down options and discuss your worries with others. You can also practice Relaxation Techniques for Stress Relief.

Avoid caffeinated drinks, or too much fluid at or near bedtime. Take care with drinking coffee in the afternoon - it can interfere with sleep. Some foods can help sleep - banana, small pieces of protein such as chicken, turkey, fish. Some foods can also disturb sleep - chocolate, cheese, and high sugar foods.  

Let your brain slow down before bed. Avoid screens (phones, computers, TV) at least an hour before bedtime. Screens give off blue light that replicates sunrise. This tricks our brain to think its morning. Download a blue light filter app that converts the blue light to an orange haze at sunset. 

Or sleeping late, if at all possible.

Try to stick to it, ideally between 9pm and 11pm.

Allowing no more sleep than you need.

So that you can't check the time during the night.

Develop a standard ritual of preparation for bed (e.g. a comforting drink such as warm milk or herbal tea, having a hot shower or bath, (this raises the body temperature, inducing sleep as body temperature falls,) and changing into cosy pyjamas. Pay attention to the place in which you sleep, making sure your room is quiet, (ear plugs dulls noise,) smells pleasant, (lavender enhances the quality of sleep,) is dimly lit, (an eye mask blocks light,) and your bed is warm and comfortable.

Learn some simple stretching and breathing exercises which encourage sleep. Yoga classes are an option.

A multipurpose room has distractions which discourage sleep. Sex, reading relaxing books and listening to soothing music are the only exception to the non-distraction rule! Take your computer, current assignment, and television to another room, or make sure they are not within reach.

If you have been lying in bed for about half an hour and are becoming distressed, get up for a while, but avoid bright light, caffeine and any activities that might increase your alertness. Do something pleasant, but not energetic, in another room until you begin to feel tired.

Think of sleep coming to you and not you going to sleep. Be comfortable in bed, focus on your breathing, and allowing yourself to drift with “no mind.” If an important thought sneaks in, keep a pen and paper beside your bed and make a note of it so that you can let it go till the morning.

Keep going with your sleep routine, don’t be discouraged if that nothing has changed. It can take several weeks for a new routine to have an affect on your sleep patterns.