^^sis mistiq, it all depends on what you like; just let your creativity flow
you can just set up a a tent or drape curtains, add some kiddie sized furniture and maybe small shelves and decorate it with stuff, much like a real salon. and you can have someone make styro signage or props.
You can buy kiddie vanities sa mall sis. yung parang princess type with the swilry bordered mirror. or just DIY it with small tables and mirrors . mas sulit sis if you can use or incorporate the furniture in your child's room afterwards.
for older kids, i guess ok lang yung trusted brands like OPI. just make sure that they don't contain harmful ingredients like toulene, formaldehyde, dbp, etc... i think there are around 4-5 toxic ingredients to watch out for. most of the time they indicate this on the bottles

for younger kids, you can try Piggy Paint, it's a brand of polish specifically for kids. I'm not sure if available locally but you can try ordering it online.
for makeup, try organic brands or once with milder formulation that's made for sensitive skin. test mo muna on your skin to make sure. we don't want the kids to get allergies or rashes

you can also do cute simple hairstyles. there are a lot of tutorials for this online.
actually sis, I got this whole idea on a kiddie party i saw on pinterest. It was an adorably cute "cinderella party" but not like the usual frufru-everthing-pink princess party (which is so cliche).
They started off with the pre-makeover cinderella -complete with apron, broom, feather duster, etc... the adults dressed up as the other characters : evil stepmom,sisters, fairy god mother, etc...
they basically followed the script - i.e. the kids had to do "chores" - they had a cute sewing station- and "clean up" - the dirty dishes were made of chocolates and desserts. And then the fairy god mothers came and gave them make-overs. and they all were given pretty dresses to wear to the ball. the pics looked so cute!
