I approached wedding planning from a zero-sum perspective. The year before I got married, I read a book called "The Eternal Bliss Machine" where the author talked about all the pressure on brides to Do Everything. The take-away from the book was to think, carefully, and decide what is important to you.
Start with the absolute essentials: Willing bride, willing groom*, license and officiant. Then, add things that are important to you and leave out the rest.
The bride planning a wedding hears from a gazillion vendors who tell her "Your wedding won't be complete without ______ (insert vendor product here)."
I was prepared for that before going in, and was ready to say "No, thank you" to those pushy vendors.
Here's a short list of things I eliminated:
Rental mens formal wear. I told the guys "Wear a nice suit you already have."
Limo. We got married at my parents' house.
Hairstylist and makeup artist. I do my own hair and don't ever wear makeup. I have "easy" hair that looks just great after a shower and blow-dry.
Bachelor/bachelorette parties. We got married because we did not want to be single any more. Why indulge in "single" behavior one last time? We were tired of being single.
Matching bridesmaid dresses. We each had one attendant. I told my MOH "Pick out something you like that looks good on you." We went shopping together and found her a great dress. No worries about what it might look like on other ladies.
Imprinted matchbook covers: I don't smoke, hate smoking, and when the stationery story suggested imprinted matchbook covers, I put my foot down so hard that seismometers in the next county registered earth movement.
One thing I did get that turned out to be unneccessary: Imprinted napkins. My mother picked them up a few weeks before the wedding, and put them in a "safe" place. The morning of the wedding, she could not find them. She searched the house top to bottom, and could not find them. A friend of my mother's offered a bunch of generic wedding-bell napkins left over from her son's wedding, so we used those and all was well.
A few years later, my mother sold her car and while cleaning out the trunk found our napkins. Oh well.
*In some enlightened parts of the world, two willing grooms or two willing brides works.
If I could do my wedding again, there are a few things I would of done different. Like Cat's wedding, ours was low-budget.
I would of had an afternoon ceremony/evening reception. Our wedding was great, but it would of been better having it later.
This is going to sound bad, but I would not have invited my cousin. She brought one of her kids (boy aged 5) dressed all in white to be the ringbearer and was ticked when we didn't use him. She also took my wedding coins (ceremonial Mexican tradition) for "safekeeping" and hasn't given them back to me!
Lastly, I would of hired a florist. Our flowers were really pretty and we got a lot of compliments on them, but it was stressful trying to get them all done. We did have the alter arrangements done by a florist.