A healthy relationship is one in which both parties are living together in harmony sharing good and "not so good", a situation where both parties thrive for a WIN-WIN atmosphere.
A healthy relationship can only come alive if both parties lay their intentions right out from the very beginning of he relationship. In essence a relationship must have a purpose. As a rule, I ensure that I get my friend to understand my reasons for coming into our relationship and also to understand theirs. This helps to prevent unforeseen quarrels from constantly coming up and also build trust from the beginning.
Laying intentions right out can only be achieved if communication is allowed to thrive among couples. "Talking and chatting" with your partner/friend instead of speaking should be encouraged. The latter involves only one person doing the "wordings" while the former involves "emphatic listening" without prejudice or any sense of judgment.
I remember counseling a couple some years back - they had a problem of alleged unfaithfulness. I told them that had they been talking and opening up to each others feeling this rancor would not have started in the first place. With much communication comes trust and respect. Communication is like cement and water needed to make a brick or block while trust & respect are the bricks so made from them.
Sharing, as mention earlier, also helps to build a healthy relationship. A relationship can not stand strong if there is no sharing among couples. Sharing happy moments as well as sad moments together is very important just as "about-to-wed couples" will agree to the "in sickness and in health, richer or poorer" statement during a wedding ceremony.
Giving and exchanging gifts shows you love and cherish your partner and sends a sign that yes you are committed to the well being of the relationship.
For a relationship to be healthy it must exhibit a high degree of flexibility and tolerance. You must be ready to accommodate certain flaws from your partner. You know sometimes I wonder why couples do not think its right to fight and quarrel, even identical twins grow up to develop different personalities not to talk of adult from different family background and values. Certainly there will be misunderstanding but the ability to be flexible, to tolerate and forgive can not be over-emphasized.
These abilities are all in us, even when it seem silent in your case, it can be culture and nurtured to radiate even from afar! Let's strive to always have a healthy relationship.