If you are looking for quiet relaxing spot on Tinos, Nostos Resort is your place. The studio I had was spacious with a really comfortable bed, well equipped kitchen and really neat bathroom. You are right there by Agios Ioannis Porto a clean calm beach.
The whole place is very well manicured with flowers and lots of greenery. There are really sweet cats roaming about like pretty much everywhere in Greece!
I recommend getting a car to explore the island and Nostos is a good base to start out from. Take advantage of the numerous hiking trails in the vicinity as well some really unique secluded beaches like Pachia Ammos and Lyftnaftia which are not far from Nostos. Antonis is a super nice host very responsive to all your needs or requests. I highly recommend staying here. You will not be disappointed.