just wanted to share my experience as I was once in the same position as many desperate mums on here. my DS is 2.1, had never gone to sleep on his own, especially day time naps! I would have to sit and rock him to sleep until he dropped off, or if he fell asleep in the car pray that he never woke up on transfer to his cot! night time he has had a routine from 4 months old, the same thing every night but he went from needing shush-patt, to me just sitting there while he dropped off, singing him to sleep, etc,etc. Until recently...for some unknown reason I lay him in his cot one day about 4-6 weeks ago, left the room, waited for the screaming but instead he just went to sleep himself! same at bedtime, and has been ever since!
my point is, even if you try every method out there and still no joy, they will eventually get there by themselves. whether is at 2,5, or 10! there is a light at the end of the tunnel so keep positive and remember they won't want you holding their hand to drop off as teenagers. that's when you get your revenge 