I suggest you talk with the child ., that is if they are old enough, and let them give you ideas and colors. Maybe favorite characters, Disney, princesses, unicorns, sports, etc. You may go it alone or include them in the decorating. Good luck

https://www.hometalk.com/search/posts?filter=decorate%20childs%20toy%20box

https://www.hometalk.com/search/posts?filter=toy%20box

it depends on the colors, sex of the child, what interest they have, etc and their age can you be more specific so we can give better answers?

Do you want something like this? I think it'd be fun to make it look like a treasure chest!

https://www.youtube.com/watch?v=PJrEyNOCXEI

You could do a cool design on it like this one - using Unicorn Spit: https://www.hometalk.com/7742521/on-the-night-you-were-born-toy-chest

"On the Night You Were Born" Toy Chest

Depends on what the child is into. If they are into baseball no brainer go with baseball bats, mitts, base balls, etc. Go to amazon.com and check out there wall decals they come in all sizes and hundreds of different designs too. Also depends on the age of the child. If the kid is 1 or if they are 16 makes a difference on what is appropriate for them.

You could hand stencil a monogram on the chest.

Keep in mind, that what is fun, now, will change as they grow older. Go for something that will grow with them.

Stencils of animals or letters for there name or something they like put a picture on it

add vinyl in the child’s favorite characters. We added Minnie heads and her name to my granddaughter’s toy chest.

How about painting a solid color some small trim and then paint the childs hand and put the handprints on the chest.... you can add more handprints as they grow up...... I have a small round table in my living room that my lamp sits on that I did this to. My kids are Grown now and it is a wonderful keepsake for myself.