1. Get the Seller to pay for some of your loan points
2. Buy a Mills Act property
The first one is not as easy. A good lender will be able to do some juggling, switching, replacing and adding and subtracting to get you the best rate. But you have to assume the seller will pay for your points, give you closing credits, or some a shave in price to help offset your rate.
Or, you can simply buy a Mills Act property that will cut your annual property taxes by between 60-70% off. Here's the math:
$1M price
Annual property taxes w/o Mills Act: $12,500/year, or $1041/month. Yes, that's like a quarter of your mortage or more.
Annual property taxes w/ Mills Act (assuming 70% off): $3750/year or $312.50/month. Think of all you can do with the $728.50/mo you'll save. Or in a lump sum, that's $8742/year. That's a vacation. Or a new Viking stove. Or nearly all your HOA dues paid for.