jules, My Yasin didn't self-settle until he as almost 2. I just stuck with comforting him to sleep and eventually he was ready to put himself to sleep. First during the day and then at night.
Now he tells me when it's time for baa' and be' and after we read a few books he snuggles up with ted bear and quack quack and I say good night and leave the room.
It took a long time but it's worth it to me because I know he's secure and happy in his room at night.
I always read 3 books to him before sleep time and at least one of them is a favourite. I think that having a routine in place really helps him - on the nights that I've been unwise enough to skip part of the routine he's always had a harder time sleeping.