Please be consistent with CC. You have to be so firm and don't give in otherwise they haven't learnt anything at all except that if they cry for long enough you will give in.
I suggest you google it properly, have a firm date that you are going to start it and really prepare yourself for it. Expect to have a couple of awful nights.
Lots of people do longer increments but what worked for us was 1 minute increments.
So I put him down after his milk and story, very kind and say goodnight. He obviously cries as I leave the room. I let him cry for 1 minute.
I go in, pat and ssh. This normally calms him down, if not, as a last resort, I give him a cuddle. Once he's calm, I leave the room.
He'll cry as I leave, I let him cry for 2 mins. I go in and repeat the calming down.
Keep doing this going up in 1 minute increments. (Each minute feels like a year!)
I've only ever got up to 6 minutes and he has fallen asleep himself.
Make sure they don't fall asleep with you patting or cuddling them- they need to learn to fall asleep by themself so that when they wake in the night they can just put themself back to sleep.
So just pat or cuddle until they are calm and their breathing has calmed down and they are sleepy. (This is so hard because it's so tempting to just keep cuddling that 1 minute longer to get them to sleep and put an end to it all!)
A couple of nights of this and they have learnt there is no point in crying because you're not going to give them anything nice. So they realise there's not much point in crying so they stop bothering.
I personally can't believe how well it works. I'm always a little bit
when I see mums tearing their hair out because their baby won't sleep and it's killing them and they're wondering what to do.
Good luck.