seabreeze,
oh that sounds like a good idea. Get a fanciful bed that they like and trick them to sleep on their own. Hope it works well.
Another way is ...this one a bit tricky ... subtle comparison?
Recently had lunch with 3 friends, all mommies with 2 kids - their elders were born at roughly the same time, likewise their 2nd one. They meet up sometimes to let their kids play together. Mommy A's boy is super clingy, while mommy B's boy is very independent. The boys know each other. Mommy A told me she once casually mentioned about the other boy, says he's very good, knows how to fix the lego by himself, go to toilet by himself, and etc etc. She says she has to be very careful not to sound like she is comparing them lah .. don't know how she does it exactly. BUt apparently it worked like a charm because her boy got very interested in what the other fella was doing and kept asking questions. within a day or two he started doing things by himself also to "show off" to mommy. Think her boy must have a competitive streak in him. hahaha