For any relationship to survive, there must be mutual understanding between the both party. If there is no understanding there won't be room for them to trust each other. And there is no trust there can never be love. Love only thrive on the basis of trust. You can't tell me you love somebody and you don't trust the person, it's impossible.
More so, there should be foundation for selflessness. Once we start pursuing personal interests in relationship, you will notice that there would be room for break up because the other person would feel uncomfortable, and unhappiness would inevitably set in. The best way to give in a relationship is to expect nothing back from it, be it material, love, care, tenderness etc. Just let them flow naturally and unconditionally.
Most relationships end up in break ups often times because everything about them was conditional. In one way or the other, one of the couple was in the relationship for what to benefit. It could be money, sex, emotional support, whatever the person was after. Once the person's desire is not met, there is problem. Break up happens basically because of selfishness. And it can only be avoided when the couples are selfless. Then we can start talking about having understanding, building of trust and consolidating on love.