Take warm milk, and increase rememberance of Allah while you are in the sleeping bed.
Reasons -1) warm milk has some incredients to boost the sleep.

Reason - 2) Shaitan he does't like you increase your credit in your account doing the great task of remembering God specialy while you are on bed coz Allah appreciated those people and prone to win your life after death due to this act., and devil, he is against this human success activity and he will change your mood to be slept faster as an alternative solution you to sleep faster.

Avoid all type of evening sleeping habits.

wear always clothes, night wear that is relaxed rather than a tight one.

this will make you nice sleep and sweet dream