There are many experts that advise you to establish a regular routine when it comes to bedtime - but why is it important?
The repetition and familiarity of a routine at bedtime will help your child feel safe and calm, and recognise when it’s time for the day to end and the night to begin.
You might want to include relaxation techniques into the bedtime routine. Examples of this might be massage or a game that guides your child through saying goodnight to different muscle groups by tensing and relaxing. You could try guiding them through visualising an imaginary place or somewhere they remember being calm or happy and, if your child is anxious about events of the day or bedtime, taking away worries can also help to calm and relax your child, by using a worry box, doll or teddy. A bedtime story could also be a good part of your child's bedtime routine.
If you are able to help your child settle themselves to sleep in a calm and relaxed way, then (medical problems notwithstanding), they should experience better sleep and also be better able to settle themselves back to sleep should they wake in the night. A regular wake up and sleep time is important to strengthen our circadian rhythm (body clock) which is responsible for regulating all kinds of hormone release, production and function.
A routine that works for you is the most important thing but here are some resources to help you with establishing a bedtime routine.