If they are Polystyrene tiles. they should be removed. If you don't want to do that or can't then, Maybe fix a Metal look tile over the joints where 4 tiles meet. either in lone or like a diamond. Use a trellis around the outside and paint it. Wood Panel it in what ever design you like. Cover it with Shiplap. Best wishes.
We’ve done tons of DIY ceilings - maybe one of these projects appeal to you: https://www.frugalfamilytimes.com/category/crafts-and-diy/ceiling
Here's a post that might help - https://www.hunker.com/12367077/ideas-for-covering-up-old-ceiling-tiles
I've used paint.
You can certainly paint it though I'm sure Hometalk has a bunch of great ideas. Try the search bar at the top left and I'm sure you'll find some good inspiration.
If it is a metal tile you can frame it for wall decor.
I would totally paint it personally :)
Do you want to keep the tile ceiling or are you wanting to cover it with another surface?
Hello. Are you looking to paint it or looking for other ideas or overlay options?