I think a nice card with memories is a great idea, as others suggested. As far as for your friend, I think the best thing you can do is to remember his date of death and keep on top of it. For the first year every month on that day she is going to be thinking about it, so just be there for her and maybe take her out for coffee or give her a phone call and be sure to mention why you're calling. My dad died 4 years ago and after time passes people forget. Some of my best friends, even my husband, doesn't remember the date without being told. I have two friends who know the date and call me each year to make sure I'm okay and it's honestly the best support I could ever get, just to know that he is not forgotten and that they know I need a little extra TLC on that day. I'm sorry for your loss as it seems he was very important to you as well.