"The sense of trust is very important, everybody has to buy into it," said McGeechan, who also toured South Africa as a player in 1974.
"Everybody has to have an open mind because, as a group, it will bring new things out. You need to be able not just to handle that kind of atmosphere it but to use it. It becomes a great strength both individually and collectively because you're playing with players you don't normally play with and you're playing with top players."
McGeechan's experience as a player and as a coach have reaffirmed his belief that every single member of the touring party should be focused on a single goal. To defeat the Boks in their own backyard, McGeechan's Lions will have to be together in everything they do.
"You've got to be pretty close as a group. As coaches, I think we've just got be honest with the players.
"We've got to deliver something and know what that is. The players have to understand that and try to do the same. There's this complete honesty and trust that builds up and you know that you have this inner support and direction to what you want to achieve."
Ian McGeechan faces a huge challenge in South Africa next summer
McGeechan will be embarking on his seventh Lions tour next summer and he expects the challenge in 2009 to be bigger than anything he has experienced in his illustrious career to date.
"South Africa are a very good side. They've got a lot of talented players. I went out there and watched them in the summer and they were very impressive.
"They're well coached and I think they proved in the final match of the Tri Nations what a good side they are when it all comes together. There's no doubt that this will be a much bigger challenge than even 1997 was."