Create a detailed timeline your wedding day that includes when flowers are set to arrive, when people should arrive, when hair and makeup will get done, etc. Include exact times and locations. Share this timeline with everyone involved in your wedding, including your photographer.
Have food on hand while you get ready. I made the mistake of barely eating on my wedding day and ended up with a headache. Having healthy snacks and lots of water on hand will make for a better day.
Practice walking in your wedding day shoes to make sure they're comfortable enough to stand around in for your portraits and for the duration of your wedding. Pain is beauty, yes, but looking pained in a picture isn't worth the discomfort.
Pack a "wedding day emergency" kit and bring it along with you on your big day. Essentials include some clear nail polish for snags, pain reliever for headaches, any makeup you need for touching up and a travel sewing kit. Band-Aids, lozenges, tampons and tissues are also good.
Have your cake and flowers arrive at the latest possible moment (but still budget in some buffer time). Flowers wilt and cakes can melt on hot days, so putting these deliveries off can ensure both look great for your pictures, ceremony and reception.
Have a "spot checker" on hand who's there to help you out with things like tangled trains, smeared lipstick or out-of-place hair. This can be someone in your bridal party or the mother of the bride, for example.
Whether you're doing your makeup yourself or having a makeup artist come in, do a trial run. This is especially important if you have sensitive skin, as an allergic reaction on your wedding day would not be good.
Order at least 25 extra wedding invitations than you think you'll need. It's better to have extras "just in case" and often times it's less expensive to buy in bulk than to order just a few extra.
Follow up with all your vendors a week before your wedding to make sure everything is in place and ready to go. Should anything be wrong (say, the florist only has you down for 4 bouquets instead of 5), this will provide plenty of time to fix the mistake.
Expect the unexpected. Sometimes things don't go as planned, and that's OK. In the long term, it's your outlook and attitude that makes for a brilliant, successful day.
I'm a Spokane Washington family and wedding photographer. I love helping to make sure your day is as carefree and enjoyable as possible. I hope these tips are helpful!