Validation is simply putting yourself in your partner's shoes and imagining his or her emotional state.

We feel validated when someone simply tells us we are right. That we aren't crazy for thinking or feeling the way we do.

***
Here is the real meat of validation. When someone is sharing how they feel. Live in their world, and not yours while they share. Let go of any personal emotional attachments, no defending, just let them be right. ***When you validate someone's feelings, it takes the fight out of them. It opens up doors, it builds their trust, and sense of safety to share with you when they need to or want to.
***

Ways to add validation to your discussion:
Listen-without responding out loud or in your head.
Repeat it back to make sure you really got it.
Take responsibility by acknowledging how you contributed to the conflict (say it in the way the felt it/ this takes practice)
Say how you think that made them feel when you did that, and ask them if you got it right. When you get it on the important issues, you will both know it, you will feel the release, the new space created for you both.