@Pan-and-Aditya0 You could use whatever you like, but what I've seen done that looks nice is to print it out (or if you have an artistic hand, you could write it by hand) and put it in a small picture frame. There are also those acrylic frames that stand up, which is what I use- it's on the bathroom counter.
Whatever you use, just try to make it look nice and something you can clean- pieces of paper or post it notes stuck up all over look tacky and can't be cleaned.
Putting some eye-catching graphic, or even a funny cartoon on posted instructions will also draw attention to something guests might not otherwise give a glance at.
