I applaud you for caring enough about your business, and your guests, to start this thread.
My highest scores are given to those hotels who read my profile, and provide me with a room that matches. Greet me pleasantly, have my keys ready, and welcome me back if I am a prior customer. Do not assume that I want points as my amenity, please ask. Understand that I may have been traveling all day, am tired, and would like to get to my room quickly - a pleasant welcome does not have to be lengthy! If you do write a card? Be sure it is accurate...I do not feel welcomed if I am greeted as a Mr. and my name is spelled wrong.
insure your front desk is trained well and is enabled to act when and where needed.
I do not require all kinds of special treatment to feel appreciated! A clean room that meets my profile and a front desk staff that is responsive when needed insures my high scores and repeat stays.