sleep training for 18 month old

[RooTwo]

Our 18 month old has always been a pretty dodgy sleeper - never really sleeping through night. I stopped breastfeeding at night when she was about 1 and her sleep got better, but in the last six months she's still been waking several times a night usually, needing anything from a quick pat to a bit more cuddling to get back to sleep. In last few months though it's got much worse and we have to be in there for ages sometimes stroking, sitting by her to get her back to sleep. That can be at 9pm, midnight or 3am. She's entirely unpredictable. I think she's forgotten to learn to go to sleep on her own - she could sort of do it, once - and that we need to do a bit of something to help her remember. Anyone done anything successfully with a baby of this age that might work?? I think we will have to do a bit of CC but am a bit anxious about it as feel she might just yell for hours and hours and refuse to lie down ... Any advice much appreciated!