This year I'm trying a slightly new system that I thought I'd share. So in years past I've relied primarily on weights but have also put one or two lines wrapped under the keel of the boat. However these lines never remain in tension.
So this year I'm trying a weight and a pulley to keep those lines under tension. I used 4 of them. The lines in the bow and stern are nice because they pull in all the excess tarp and leave less of a wind target.
All the anchor points are golf balls with slipped bowlines constricting around them. I'm a bit concerned about chafe on the lines running under the boat, I've seen it in the past, so I added a back-up line for the weight on the pulley line in-case it fails.
My frame is just two sawhorses (one tall one over the cockpit and another on the deck) with strapping boards running between them. I did a better job anchoring the sawhorses because last year they toppled in a wind storm (although the tarp remained intact).