You're supposed to take care of the bride's bouquet, your groomsmen's boutonnieres, and the corsages for both mothers and the grandmothers. You may, however, want to leave the actual choosing of the flowers to the bride. She probably has a much better idea of what she's looking for in her bouquet, and she may also have very strong ideas about what type of flower she'd like for the groomsmen's boutonnieres. One way to be helpful here: Suggest looking for a discount or wholesale florist. Then stand back and let her get to work.