Tissue is invaluable to keep your gown in tip top shape. Stuff the bodice with enough tissue so it it is fully filled out, and stuff the skirt with more tissue to prevent creases.
If you are traveling by car to the wedding site, lay the gown on the back seat of the care. If traveling by plane, most bridal shops will pack your gown so it arrives in perfect shape.
Be sure to bring an emergency care kit to the wedding. A small kit should include needle and matching thread, a small pair of scissors, and extra beads and buttons. Check with the bridal shop if they would recommend a stain remover, just in case that glass of red wine tips.
When having your gown cleaned afterwards, choose a facility that understands the needs of wedding gowns. Resist storing it in a plastic bag, that will trap moisture. Acid free tissue and packaging is recommended to keep your gown looking fresh.
Consider having a keepsake made of your gown, perhaps a purse for your future daughter to use at her wedding, a quilt or even a cherished baptismal gown that can become a family heirloom.