Until they are one year old they decide.
Around one year they can learn to sleep well.
Every parent that kids needs to learn to eat and drink from cups.
I also understood and enjoyed helping my oldest daughter learn to walk.
But for some reason it never occured to me that sleeping is something that many kids will need to learn.
The basic rules are simple.
Part 1: make sure the environment don't change while they are asleep
After a certain age:
- never let them fall asleep with a bottle
- or while you are singing or saying prayers
- or listening to music
- or watching tv
Do read stories, sing, play and try to make sure they are happy when they go to bed. Just make sure they are awake.
Basically they shouldn't fall asleep in a state they won't be in the next time they turn around furing sleep.
Kids after a certain age should fall asleep in their own bed and on their own.
Part 2:
Kids should not be afraid and cry themselves to sleep.
But if you just leave them alone in their bed they will.
Instead say some magic nice words that you decide, then walk out. Start a timer for one minute. Walk back in (even if the kid isn't crying) say the same words you said when you left. The rest of of the night until the kid fall asleep (i.e. not until the calm down) go back every 3rd minute, i.e. every 180 seconds, sharp. Use a timer. Say the same words.
The next day use 3 minutes first and 5 minutes the rest of the evening. Use a timer. Be consequent.
What you want to teach is you are going to be there for them either they cry or not.
Don't stop until after they are asleep. (I happily go back two times more and I don't care if it seems they are sleeping, if tjey open their eyes they'll close them just as fast, now convinced that you are still there.) If one stop going back when they calm down then they understand they'll have to cry to get attention.
Next day 5 and 7 minutes, then 7 and 9 etc. By now they are probably relaxing after a few minutes.
Except for my first who had already gotten a bad habit by the time I started teaching, the rest picked it up in 3 or 4 days. After that they'd enjoy going to bed.
Two more things;
- make sure somebody can hear them if they wake up in the night. Mostly because who wants their kid to be afraid, but a nive side effect is they learn that thet are not forgotten.
- do sleep training on good days (not when new teeths are arriving or while they have the cold)