Getting the last couple straps nice and tight on a shooting jacket can be a challenge, especially if you are a little round in the middle like myself.
I stumbled across a post on the CMP forms where someone recommended attaching the straps first then zipping up the sides. Of course this only works if you have the “all position upgrade.”
While this works it’s difficult to work the zippers when all snugged in to the jacket. So I added a bit of para cord to all of the zippers. Super simple, but it makes it much easier to pull the zippers on the jacket. I also added a shorter piece of cord to the arm zipper (used for off hand) as on several occasions I have forgotten to close it until I was all strapped in for prone. This way I can grab it with my trigger hand.
This method helps me keep the jacket nice and tight which keeps my hips a bit stiffer and keeps the jacket from riding up.