Forget all the fancy stuff, just use heavier straps!
If you buy On Sight straps from MEC they are too heavy and inelastic to vibrate in the wind when tied tightly.
I find that only cheap, thin, or stretchy straps vibrate…
I haven’t had any problems since I switched from the cheapo thin straps to the On Sight ones….. They have a uniform stiffness, so the pressure is applied evenly over the entire strap, not just down the centre…
You should know how to tie knots anyways… Practicing with your tie downs is a colossal waste of time… Especially when it’s -3C and the wind is howling!
Unless of course you’re an open-boater… Then you should use ropes to fit in with the rest of your stone-age equipment
(If you just chuck the leftover strap in the door and close it you’ll be the fastest boat-slinger in the West!)