On loose stuff shift your weight as far back as possible. Smooth throttle with slight positive input. And a good butt sensor to let you know when to apply a little counter steer.
You're already at a disadvantage in the dirt with that 883 Low because ergonomically, it's not conducive to quick weight-shifting. When you're cruising on a dirt/gravel road, just let the front tire "hunt" and don't fight the handlebars. The "hunting" is just the smaller radius (edge) of the front tire being drawn into a ridge it has contacted. Let it ride into the ridge and over it and it will find another one. Kind of like a Beagle on a leash with its nose going back and forth. On a good gravel road, I usually cruise at about 60. For turning or cornering, you have to countersteer, "get on the tank" to weight the front wheel and accelerate to slide the rear wheel around. Dropping the inside foot off the peg will help lower the bike's CG. Buy a small dual sport or trail bike that you can easily learn to control and just ride the hell out of it. The better you get in the dirt, the better you'll be on the street.