If they wake at night, try to keep your child in their bed. It reduces stimulation and makes it easier for them to get back to sleep. Getting up for a snack or drink, going into a brighter room, makes their body think that it’s daytime.
At bedtime, some families try a 'free pass' idea if their child keeps getting out of bed. This is a pass/ticket that's good for one acceptable request (another hug, glass of water), that they hand over after using. It's time to settle without getting out of bed again.