While it is impossible to make a child go to sleep, it is much more possible to get them to put themselves in a position where they are likely to fall asleep.
Typically, it is best to incorporate this strategy into what happens during the bedtime routine.
For instance, if you read a book to your child, make sure that while you are reading the book, they are laying down completely under the covers and in their pajamas.
You might have two parts of the reading every night, the first part you can do without requiring anything and the second part is the bonus reading which you can only do if they are laying down under the covers with their eyes closed. The bonus reading can only be had if they choose it. Now you have set up a scenario where they can autonomously choose the second "bonus" reading and you can help them put themselves in a position where they are very likely to fall asleep.
That conversation might sound like:
Ok, so we finished the regular reading. Do you want me to read the bonus section?
Yes!
Ok, so I need you to close your eyes and be under the covers and we can start the bonus reading.
I don't want to! I want to look at the pictures!
In the bonus reading, we can imagine the pictures. We don't have to have the bonus reading, but if you want the bonus reading you're going to have to close your eyes.
I don't want to close my eyes! I want to keep them open!
Well, you can keep your eyes open, but I can only do the bonus reading if your eyes are closed. If you want to keep your eyes open that's OK, I just can't do the bonus reading. I'll sit here with you for ten more minutes, but since it is sleep time, we can only sit quietly.
The conversation with your child may continue a little further, but at this point you have established the contract of being under the covers with your eyes closed gets you more reading time and attention, whereas not being under the covers with eyes open gets no more reading time or attention. Wait ten minutes in the room for the first option to be chosen, and after that the window closes. While you are waiting, there is no need to talk further or engage the issue. Its not a big deal! They can choose to spend this ten minutes in a really boring way, or they can choose the bonus reading. After that, it is “lights out” time.
This tool that I’ve gone over here is a basic tool that I call "mapping" that I am going to talk more about in the 2nd edition of Raising Lions coming this winter.