Book one location for your ceremony and reception to avoid multiple site fees and having to provide transportation between venues.
Cut out the champagne and let guests toast with whatever drink is in their hand.
If you're a stickler for tradition and can't live without a wedding cake, choose buttercream or cream cheese instead of expensive fondant.
To save on flowers, use lush greenery in your centerpieces.
Buy in-season flowers wholesale and then pay a florist to do simple arrangements (or you're crafty, then you could DIY!).
Hire a student quartet from a local music school to play during cocktail hour or during your ceremony.
Instead of paying extra for your invitations to arrive assembled, gather friends and set up an assembly line.
If a photographer whose work you love is out of budget, ask if you can wait until after the wedding to order proofs and albums. Save up, or use some of your gift money later.
If fancy wheels are a must have for you, a limousine will be cheaper than a stretch SUV. And if you don't mind taking your own ride you could hire a private chauffeur to drive your car, which would be much cheaper than hiring a limo.
Do you have a relative who never puts his video camera away at family occasions? See if a professional videographer will edit amateur footage — it will cost a fraction of the price for having the professional shoot the wedding.