This was just one I found in the info above.
Buy Down Your Rate
I know it sounds like a car dealer trying to sell you clear-coating when your mortgage lender talks to you about buying discount points, but this can be a really good way to reduce your payments if you have the extra cash to spare and will be in your home for a while. You can typically purchase one discount point for one percent of the cost of your mortgage, with most lenders limiting you to the purchase of three points. Each point will reduce your rate by 0.125 to 0.25 percent, for the life of your loan. That can mean some serious savings over the life of the loan and a modest reduction in your monthly payment.
When you were borrowing the same $150,000 at that 4.27 percent conventional rate, the monthly principal and interest payment was $739.67, but by buying just one point, you’ll reduce your rate to 4.02 percent and the payment to $717.85. More points mean bigger savings, as illustrated in the table below