Can I suggest a book? Its called "Raising a self-reliant child". In the chapter on sleep training, it suggests teaching your baby how to self-soothe. You basically let them cry it out, but only for a certain a mount of time. For example:

Rock child to sleep, when they are drowsy and almost out, put them in bed and leave the room. They will likely wake up and cry. In 10 minutes, come in and rock them again, and then when almost asleep, set them in bed, and leave.

You keep doing this, with longer periods of time away. They learn you'll always come back to soothe them, but they eventually learn to calm themselves and fall asleep since you're gone for longer and longer (and they are tired!).

Best of luck :-) disregard if that's totally not something you'd like to do.

Putting toddler in crib