How to make a relationship last

I can't tell you how to make a relationship last for life or decades because I haven't done that. But If I had to answer that to the best of my abilities right now, I would say,

1. Be with the right person.

Someone that you actually like and respect you know, someone you could be close friends with even if you had no romantic or sexual desires whatsoever.
To put it bluntly, if tomorrow someone chops your mandrel off, would you still be Interested in your parther? There's your answer. :)

2. Don't take them for granted. 

As time goes by it becomes easier and easier to forget what you have, it becomes mundane to you and you shouldn't let it, cause it isn't.

3. Talk about everything.

Don't leave stuff unsaid, don't let frustrations build up. In any good relationship you're always on the same team so you have to trust each other, you have to work things out together. Disagreeing over something and fighting over something, while that's not something you want, that it's not nice,
 it's probably a lot less damaging than quietly drifting apart because you're keeping things to yourself that need to be said.

All Credit for Dean Leysen. Just spreading the love,advice and just the reality of it.