1. Be Consistent
Sleep and wake up at the same time daily. This will help anchor your body's circadian rhythm.
2. Warm Colours
Use only warm coloured lights at night and reduce exposure to blue lights. Examples are florescent lights & computer screens.
3. Cool environment
Keep you room temperature cool and purchase mattresses that breathes well. Mattresses made with natural materials like natural latex breathes well and maintains a cool sleeping surface.