Some friends and I are sending flowers to a close-friend's grandmother's wake. I think a simple white wreath would help us show our sympathy and express condolences in such a situation.
You haven't been to a funeral till you've been to a greek orthodox funeral. The whole community comes out, and helps the family mourn. Its a very sad affair, but I noticed that the number of people who came to the funeral was very important to my family. Maybe it helps us realize how connected lives are, and how appreciated the person who passed is.
If you are invited to a funeral you should make the effort to go. And shiva's too!