How to have a good relationship?

I discovered the key to being happy in a relationship a couple of years ago and found this quote Eric Lippert's blog to be closest to my epiphany:

Riddle me this, Google:

"More generally: I've learned by bitter experience that it is a bad idea to predicate your own happiness on the behaviour of other people. It seems crazy, I know, but one of the best ways to have a good relationship with someone else is to first learn to be happy by yourself. Happy single people are highly attractive to MOTASs compared to desperate, depressed single people."

Interestingly, Madonna croones about this too in Secret:

You knew all along
What I never wanted to say
Until I learned to love myself
I was never ever lovin' anybody else

So there you have it, expert advice from a single man :)