Another nice gift might be manual grinders. I wish I had more! These are great not just for salts (and you could totally get them different types of salts to go in them, such as Himalayan Pink Salt, Hawaiin Black Salt, Sea Salts from various different regions and even seasoned salts. Salt Works has a lot of different types of salts and they ship. They have wholesale prices that are fantastic. If you were wanting to buy pounds of salt to get ready for the apocalypse or to do lots of pickling, their price is fantastic. Salt doesn't go bad, so you could buy pounds of it at a deep discount and use it for years. We love their Himalayan Pink salt, and my mother has the Hawaian black salt which is delightful, too. Their Pure Ocean sea salt I believe has the best value of all their sea salts.)
Aside from salts, grinders are also good for whole spices like coriander and different types of peppercorns and even fennel pods.
We have one like this one here and I love the ergonomics of the cranking ones, rather than the ones you have to twist.
The ratcheting type like this one are also really nice and ergonomic (we were given some as gifts and they are great for salts. My husband kept breaking them when using pepper in them), but I wish that they weren't plastic.
Like measuring spoons and cups, I don't think anyone can every have enough grinders! Some grinders are really beautiful, too. My mother found a marvelous hand crank grinder at a thrift store--it's the best grinder we have, and they usually retail for almost $100. It's worth checking thriftstore for affordable finds--just test them first to make sure they work!