Three ingredients for a healthy relationship

Respect
There must be mutual respect between two people for them to have a meaningful relationship. The respect must transcend superficial tolerance toward each other. Rather, it must be a deep seated willingness to accept each other's characteristics and quirks without prejudice.

Openness
With mutual respect, both parties must be open and transparent with each other. There should not be any secrets or hidden resentments. Any dissatisfaction must be sorted out immediately in order not to allow it to grow and pile up irreversibly. Open communication is vital toward the success of any relationship.

Patience
While respect and openness are fostered, there will be times when either person will experience a breakdown and thus bouts of emotional bursts will occur. This should never be taken personally, and instead of confronting it, the other person must have the patience to let this subside.

With these three ingredients - respect, openness, patience - a truly healthy relationship can be formed and sustained between two people.