We didn't leave DD to cry it out or do controlled crying but now she can self settle. We went to sleep school to help us so here's what we do which I think is NOT cruel.

Like others said - watch for tired signs and get them to bed as soon as you see one!!

We let DD protest but not cry for short time (usually around 2-3 mins). If she is crying we start the settling straight away but if she is protesting (calling out or whinging rather than crying) then we leave her. 9 times out of 10 she falls asleep within 5 mins.

To settle her we sit by her bed and pat her or the bed until she settles. We never leave the room unless we've been there for AGES and want to swap with DH. The first couple of times it did take up to an hour of this patting and it was hard but we NEVER left her and we were always touching her or the bed so she knew we were there. We also whispered to her that we were there and that it was okay to sleep now.

After 2-3 nights of doing this she has learnt how to self-settle really well. Of course we still have our moments but she is SO MUCH better now and we get 10-12 hrs each night.

The other thing is that they should have good day sleeps in their cot (when possible). Alot of people will say that it doesn't matter as long as they sleep at night but we found DD needed her day sleeps - the saying "sleep produces sleep" really worked for us. As she has gotten older she needs less sleep and can still sleep through night but she needed 3 good sleeps each day to sleep well at night.

Hope this helps!