We’ve posted some tips based on our experience that we feel will be of good value to you. I don’t claim to know it all, but after many years in SF, these tips and techniques worked for me and hopefully, they’ll work for you as well.
Your weight should be packed up high between the shoulder blades. If your ruck has radio pouch up high, that is where the sandbag or weight plates belongs. I prefer sandbags because it will mold to your pack and back and doesn’t have any sharp edges that can rub you on a ruck.
On this particular practical exercise I used the waist strap on my rucksack, that way, the weight rides on your hips and you can loosen your shoulder straps a tad so that the weight isn’t all on them.