With Honken Dahlias, I've been able to set up a coupon code for free shipping on multiple orders. Theoretically, a buyer could use the coupon for their first order, but so far I haven't had anyone try that. I find I break about even charging $9 flat fee for all orders even with the coupons. I'll probably raise that to $10 this season as rated went up this year
I loose some on the big orders but make some back with small Midwest orders I send via First Class. There are a few tricks to keep costs down. For one, I don't fall for the Flat Rate "deals" with USPS. They almost always cost more.
