I've made a few masks (need different colours/patterns to go with outfits 😂)
Ties made with ribbon or bias binding are much more comfortable than elastic
If you're not the sewing type lots of crafty people are making them, maybe look on Instagram there are loads there. I know one account, fortunes antiques I think, has some in lovely chintz prints and plain fabrics. She's in Dublin/Bray I think so post would be quick.
There's also a great tutorial for making a mask out of a t shirt, part of the sleeve forms the tie, it's very clever and easy to do. I'm sure it must be on YouTube. You need zero crafting ability to make it.
If you are making your own the fabric needs to be quite heavy, hold it up to the light, you shouldn't be able to see light through it. If your fabric is light, double it over.
You need to take them off carefully and wash after wearing. I guess Ryan Tubridy will be teaching us how on the late late soon. Remember those innocent times when he showed us how to wash our hands? Seems like a lifetime ago!