There's loads of different methods moose. Our babies are too young yet! I don't know what the suggested age for sleep training is, but we did it out of desperation with DC1 because DC2 was due and she was still waking 5 or 6 times a night aged 12 months - and needing a massive ritual of rocking/singing/shushing to get her back to sleep.
We did increasing 5 minute gaps to 30 minutes. So put her to bed with dummy (on ribbon attached to sleeping bag, so she could always put it in herself) knowing she was fed, comfortable, not in pain and tired. But we cut all the procrastination out. Just nan-night, kiss, into cot, leave. She went ballistic.
Waited 5 minutes. Went back in, picked up, nan-night, kiss, into cot, leave. Then 10 minutes picked up, nan-night, kiss, into cot, leave. Then 15 minutes, then 20 minutes, 25 minutes, 30 minutes, then every 30 minutes until asleep. All the time DH and I sat outside her room supporting each other because it was so hard to stick to your guns in the face of such desperate pleading from your baby. Too over 3 hours first night.
Works. I would imagine it is not very "mumsnetty" since it is very harsh.