On each table we had a small vase with a floral arrangement in it. We picked out the flowers at a local floral shop -- which smelled absolutely amazing -- and grabbed some greens and leaves as well. The green flower hiding behind the big white one is actually a carnation that we picked out in celebration of our Mom's birth month.
Also, as part of the centrepieces, I had my mom pick out a couple of photographs from each decade that she has been alive, and then I had her dictate to me what was happening in each photograph. I typed each little story up and placed them next to the corresponding photos. A lot of people said it sounded exactly like she was talking to them herself.
On the party invitations I requested that guests bring along a favourite desert to share at the party. Along with all of the deserts on the table, we placed a large vase with sticks and pussy-willows where guests could hang a small paper circle that they had written birthday wishes on for our Mom.
These days, it wouldn't be a proper party without a photo booth with some fun props. I got a lot of inspiration for the photo booth decorations from Pinterest, including a tutorial for making the paper fans.