Roses symbolize love and there are a number of creative ways to incoporate a rose ceremony into your big day. It's a great way to involve family as well.
In one version of the rose ceremony, the couple give each of their mothers a rose as a token of their love for family. This is often kept a secret from them until the roses are presented. This can be extended to include other members of the family or even to mark the absence of a loved one (by placing the rose in a vase).
Roses can also be exchanged as the couple's first gift to one another as a married couple. This starts a tradition in which the couple gift each other a rose every year on their anniversary.
Here are some examples that you may want to consider: