In a column in England's Rugby World magazine, he said creating an environment of care was the most significant thing he looked at in coaching.
"I care about how players are going to get better, and I care about their well-being in what is a tough sport.
"If I provide enough care for players, they'll care about themselves; they'll care about their performance. That approach makes you accountable, but there is a lot of love in it too.
"It can be tough building an environment, but at the Crusaders, we don't use the word 'challenge' – we ask, 'Could we do that better?'
"It's not threatening language. We talk a lot about the idea or the theme for the week or the season.
"It all comes back to the overarching question: what's our mission? Then, we'll talk about it, battle it out on how we get better. We are all pretty close, so we do that, then take a step back."
Robertson said from the time he turned professional, he loved the game's camaraderie and the teaching in the game.
Former All Blacks and Crusaders coach and Women's World Cup-winning coach Wayne Smith taught the Crusaders the game when it went professional in 1996.
"He came in and talked to us about defence, the mindset that is required, structures, individual skill-sets. I just wanted to be involved with this as much as I could."
When he first coached the Christ's College Under-16 B team, Robertson started to carry a notebook.
By then, he had played in Northern Ireland and Scotland and learnt about himself while meeting some people who influenced him.
"I knew I could play and could do something with the gifts my mum and dad had given me. So, I made a promise to them on the way home. First, I apologised for some of my teenage behaviour. I told them how I was going to be committed and how I was going to become an All Black and get a degree.
"Those two or three years were a way for me to find out who I was, but also what I wanted to do, what I wanted to achieve."
At the same time, he said it was important to know what your strengths were and what areas you needed support.
"As a coach, I'm a great ideas man, but I also need people that are finishers. I need experts in different areas, and I need people to help me tell the story.
"I've grown and evolved because I know what the current group at the Crusaders need. However, over time you look at the game differently, too. You mature, you learn things. Things that used to worry you earlier tend to wash away."
He said the organisation was also willing to talk with people from outside through their coaching leadership programme. That process also had benefits that helped the Crusaders reteach themselves.
"We're not threatened by sharing our information. Because someone has still got to put that into practice. It's in our nature at the Crusaders to share."
It was also good for recalling all that had been achieved and sometimes forgotten.