I just planned my own rustic themed vow renewal ceremony and it was much like a rustic themed wedding. One of my favorite resources and inspiration website is www.rusticweddingchic.com. They have so many things to help you formulate a plan.
I suggest a rustic barn or old house setting for the venue. You can use lots of mason jars with flowers, old barn wood for signs, chalkboards for signs are good too. Lace and burlap are big. I can share some pictures if you want.
I was a a rustic themed wedding not to long ago. Some ideas they had were old picture frames as their centre pieces as well as horse shoes. Another idea they had was specific area dedicated to a place to take photos. It was a wooden backdrop with hay bales and old crates, jugs and mason jars. If I had the pictures still I would show you!
Hope that helps!
Wedding & Event Coordinator
here's some ideas; paper-straws for the drinks, haystack-seating outside, board on a barrel as a table, cake on a chopped tree trunk, veteran car for transportation, boots for the bridesmaids, wooden crates (can be used for many various things)
Flowers: Something simple, white flowers with greenery. Tie bouquets together using a twine
Centerpieces: Mason jars, to add a bit of glam you can paint clear glue on the inside of the jar and fill the jar with glitter and let it stick to the glue. Place a candle in the mason jars.
Bridal Party Shoes: cowboy boots
Signs: Post cute signs on a chalk board
Invitations/Menus: Use thick card/brown paper
Silverware: wrapped in burlap and twine
I could go on all day!
I hope this helps