Honoring Your Mothers 

To honor the two mothers at the wedding ceremony have your florist add two floral sprays that can easily be removed from your bridal bouquet. When you have made your way up the aisle pause and remove one floral spray and either hand it directly to your mother or give it to your escort to hand to her. Be sure to let your escort (father, brother, friend, etc) know in advance what you want to do.
As you walk back down the aisle as husband and wife after the ceremony, stop briefly where your new mother in law is sitting and hand her the second floral spray.
Be sure to keep this plan a secret from the mothers to make this a memorable surprise from you. Everyone will love it!