Great question! Three things saved me a bundle this year:
1) Paying my property taxes/insurance directly rather than through mortgage escrow. Saves me $50/month that they were holding, as well as gave me a refund for $1700 or so that was in my escrow account.
2) Consolidated my homeowners and auto insurance with the same company (saved $550/year), and got a 10% discount through my alumni association.
3) Bought a new car using GoldStar directory, though I'm sure most corporate buying programs/internet quotes would do just as well. Saved $1500 more than Edmunds' target price, which I would probably have trouble getting on my own.