I put raw meat into the bag sealed on only 1 end. Let the meat get semi-frozen then seal the bag. I think this is a technique from my old Foodsaver manual that keeps the sealing pressure from squeezing a lot of liquid out of the meat and fouling the seam sealing process.
Then I often put several sealed bags inside a large Ziploc bag just as a way of protecting the sealed bags. If you get a nick in the sealed bag from it jostling around in the freezer against other stuff, you lose your seal. So the Ziploc kind of takes the brunt of things, not the precious sealed bags inside.
Regards,
Chris