Formal with respect, true love, fun... a long relationship. Where you and your girl/boy are disposed to struggle for their love, a long relationship. Currently, it's very common to see relationships that have a duration of one week or month so, what is happening? Don't we are enough patient? it looks like if people currently are not able to create or feel true love.
I am happily married after 30 years, and I will share some tips.
First: the word is RESPECT. In Spanish we said "La confianza da asco" (confidence sucks). It's very difficult mix both concepts, confidende and respect. But for me, it´s essential.
Second: EMPATHY. When you think the other person is at least as important as you, it's easy understand his/her needings and supply it.
Third: RESILIENCE. Not every day is a good day, for you and for your loved person. You must accept and deal with it.
Fourth: WORK. Try to be lovely for your loved one. Compliments, kisses, little touches, hugs... Be more sensual than sexual. We said: "El roce hace el cariño" (touch makes affection).