I will give you some advice:
When you see your children do not ask them about their mum
Do not ask where they live
Do tell them you love them and that you are sorry it came to this
Do not miss any contact access dates
Do not forgot their birthdays or christemas
Do ask about their life - school, friends, activities, likes and dislikes
Do listen to what they say
RESPECT what they say, their feeling and opioins
Do not control what they should think, believel, feel or want.
Read parenting books to help you understand their development stage
Do not laught at them, disrespect them, do not be sacastic, do not put them down or make them feel bad about themselves in any way.
Support them in being themselves
Praise them
Make them feel important to you but do not control them
Be a better person and a better role modle than you have been, everyday even if they cant see you or know.
DO NOT EVER PLAY MIND GAMES WITH YOUR CHILDREN TO GET BACK AT YOUR WIFE