Writing a message of condolence

I recently had a good friend who passed away and I wanted to send his family a card with a message of condolence inside. 

Are there any set phrases in Chinese that I can put inside?

I wanted to say something like:

"I have fond memories of him. I am pleased I had the privledge of getting to know him, travelling with him, and learning from him".

Any help would be greatly appreciated.

:)