The cheapest trick? Cut that guest list mercilessly. Every guest is another meal, another favor, another invite, another sliver of your centerpiece. Start with four lists; your, your partner's, and both sides of parents. Then switch lists and use a different color to check everyone you want to invite from each list. The guests with four checks get to come; the guests with three checks...probably. One and two checks?  Up for discussion.

Cut out the +1's for anyone who is not engaged, in a long term relationship with someone you recognize, or married.  

Check out upscale bridal consignment stores for great gowns and accessories.

Think about Thursday, Friday, Sunday and Saturday morning as viable times to have a party. If your wedding is in the summer or during the holidays, your guests will be very used to going out on nights other than the weekends, and you can save a bundle of cash.

Think 'off season'; January, February, November. Winter for weddings at the New Jersey Shore.  Better. Cheaper!!! Less crowded (but the flip side of this one is that more people might be available to come to your wedding since there is NOTHING else going on!)

Go family style!  It cuts down on staffing, and your guests have a chance to really mingle while they are passing dishes around. It's fun, rustic and totally personal. Don't do the entire meal this way; serve the salad and dessert, but just do a family style entree.