Getting my four-year-old son to stay in his own bed has been a challenge. He keeps crawing into our bed in the middle of the night, especially when he senses someone is awake or has a bad dream. After much trial and error, we've found that creating a highly rewarding and enticing "big boy bed" routine worked.
We made a big deal out of him graduating to a big kid bed and let him help decorate his new Spiderman-themed room with wall stickers and a new bedtime buddy - a soft toy he chose himself. Each night, we tuck him in with a different exciting routine that rotates every two nights: one night is a special story time with Mom; another is a fun, calming yoga session incorporating animal poses and lots of giggles; and the third is a Spy Mission with Daddy, complete with flashlight play and silly espionage roles. He feels like he's achieving something big each night and is motivated to stay in his bed, excited for the next installment. This has encouraged him to settle in his room alone, giving us uninterrupted sleep too.
I'll be interested to hear other moms' methods that encourage independent sleeping! Some consistent routines definitely help, so I'd love to glean more ideas!