Help your kids feel at home in their room by inviting them to help choose a colour scheme for the room. If they can decide or agree on colours, stick to a neutral colour scheme and allow each child to add pops of colour with scatter cushions and artwork.
You could also add individual name appliquéd or printed decorative pillows to make it clear who sleeps where. Get your kids to make their own art on matching sized canvases to be hung above each bed.
Another fun idea is to use self-adhesive hooks, twine and bulldog clips to help create a hanging artwork display for each child on their side of the room.
The bedroom above by @cassmiller is a great example of how to liven up a neutral base colour (white) with pops of colour and sweet personalised details.
Remember that, the more fun your kids have when setting up their room, the more likely they are to love their shared space. Happy decorating.