How do you make a baby sleep?

Nourish and nurture. You identify and fulfill their needs. If they're Fed, changed etc.. Spend some quality time with them. Bond. Feeling safe is important too.

Set their sleeping environment right.

I get my friend's baby to sleep often by giving her a bit of food and after putting her down a 2 minute belly rub. She's usually out in no time and the parents have no idea how I work my magic.

you keep them on the bed and let them fall asleep 

Singing a lullaby may induce slumber.

I dunno.

Nursing babies to me... is like baking.

I cant do it.