Who doesn't like a nice surprise every now and then, that being said showing that significant other that you are thinking about them is never...EVER... a bad thing. Not a single person on this great earth does not want to feel loved and assured that they matter. so surprise one another with a token of your love whatever it may be its the thought that ultimately counts, diamonds can be a plus one also tho.
Material objects should NOT define your relationships but like most things they have a time and place.
There are indeed two sides to every emotion. If you reward your lovers positive attitude with gratitude, they will present that same feeling again to you (and if they don't they are definitely not the *one*). Showing others who one really is without exaggeration or deception is paramount in any good relationship.
People like this will slowly drain you of the energy it takes to make a relationship work, (and lord knows it takes a lot of time and effort to make them work) its just not possible for a relationship to be in a good place if the significant other is constantly draining you with issues and constant complaints, fact is this type of lover won't stop until you and the relationship have completely run dry. Never give people permission to suck you dry, make it known that such actions are unacceptable and you will not stand for it.
Who couldn't use a well placed compliment? Compliments often make your partner feel good and everyone loves to feel good, plus it shows that you care (caring is a good thing!). Keep it genuine and never be afraid to speak from the heart. Love is a genuine compliment.