One of the things I love to do with my 6 year old daughter is to give her a weekly Saturday manicure and paint her nails. This whole routine started when she was around 3 and had just started preschool. She was very nervous and started to bite her nails. I saw her future flash before my eyes, stubby nails, irritated, painful cuticles, other girls pointing and laughing. There are many things I can't control in her life, but one thing that I did feel was my responsibility was too teach her to not bite and how to take care of them. So now every week they get a trim and polish, and every few weeks I do the whole mani-pedi thing.
We spent a days at the beach a couple of weeks ago and she wanted something bright and colorful so sherbet nails it was! Colors I used were from the now sadly discontinued Sephora by OPI collection. The light purple is It's Hippo to be Square, the peachy coral is How Cute is That, and the pink is Access 24/7. 2-3 coats per color with Seche Vite as topcoat.
It's very easy to do if you have a steady hand and a steady kid. I started with the bottom color, painting one stripe at a time in each hand, working my way up.