Any of my outdoor shooting compatriots using the PD Capture Camera Clip on their packs? A lot of folks at FM are swearing by it, wanted a little more feedback before I throw $70 at a piece of metal.
https://www.peakdesign.com/products/capture
The Capture clips are godlike. It'll take a bit of practice before you can just slide it in, but it's really secure, can be locked, and is way better than a sling for when you're around and moving. Typically if I'm walking around, I'll have my camera attached to the leash, and then the Capture clip on my hip. That way, I can have it clipped on and not dangling/swinging around as I walk around, have my arms free, but still have it tethered for in case something happens while I'm using it.
Using it on a backpack works better than a belt clip, mainly due to the weight of having a camera on your hip. That being said, I use mine almost exclusively on my hip due to never wearing backpacks, and I'm super happy with it.
If you plan on using it on your belt though, I'd definitely consider getting that belt loop pad thing they have, it's more comfortable that way.
If only they'd make a Capture Lens for Fuji. &_& It's the only thing I regret about switching is they don't make that.