Squeaky hinges on internal doors

Rubbing the lead of a pencil on squeaky hinges used to work, although I haven't tried it for years.

Rub with dry soap bar. Work it in. Works very well.

Thank you for all those suggestions.
I'll work though them from the top!

I didn't know about the dry WD40 - that sounds very useful.

My go-to solution is olive oil. Wasteful but it works.

Mr. B uses gun oil, very effective. Sewing machine oil would probably work too. Don’t use too much, it’s counterproductive.

Vaseline

I used olive oil when I didn’t have any WD40, it worked.

I always use a tiny bit of butter or Marge I ve done my daughters doors today the teenage grandkids think I some kinda witch as none of the doors squeak now

WD40 but the dry PTFE version.
It's done amazing things here.
Good luck.