I agree a fence is a must, and our pup loves to lay in shaded thick grass. And dig holes and lay in the dirt.
And making it attractive mostly for my own eyes. Maybe just keeping it kept up and clean of doggie messes.
List of ideas/projects
*maybe synthetic dog safe grass
*automatic water bowl
*designated digging area with hidden bones.
*long dog run behind pool cage.
* doggie pool
LoL. All good ideas, but honestly, all you'll need is a fence and, if you don't want them doing their business on the grass itself, a cement pad. As for the digging, maybe have a sandbox the dog can dig in so they aren't digging up your garden and you can hide stuff in there.
My yard is fresh cut with a section of tall grass as it's a great place to hide doing SAR work and it leads right into the state park behind our house.
Set up some PVC jumps, weave poles, simple things to build and your dog to learn to navigate. More likely than not...they won't just randomly use large obstacles in the yard. They're not going to exert extra effort for no reason. If you have the space/money a pool or a pond might be exciting but if you're just talking regular back yard, take yourself and a tennis ball and I'm sure they'll love it.
river rock(larger than pea gravel) helps keep my yard/deck area cleaner. I have a coatie too...not much can keep them from dragging in the whole back yard.
We have extensive decking, concrete patio and then the river rock, and there are still areas of run down grassy area that turns to sand.
My yard is only 1/8th acre and only 2/3rds of that are fenced. Huge garden where they can't trample on it and having the fence set back 20 feet keeps them from scaring people walking their dog past our house.
The fence is setup like a U around the house. There's little grass left on the far side of the yard because that's their potty area. I brought in sand for their potty area last year, that works excellent
I put a garden up against the fence and my vegetable garden is round so they have a race track around the short fence for that. I have a lot of short fence, 24" so I can step over it but the dogs won't run through it. Lots of 18" hoop fence too. Dogs respect hoop fence if it's tall enough and you teach them.
In the back, I replant the grass every year and there's garden beds up against the fence. No more than 8 ft long with look out spots for the dogs. Some of my beds are raised wtih rocks around the boundries of the garden. Dogs respect rocks and tall hoop fences.
Everything I built for gardens, I put paths either behind them or through them. Lots of pathes and tunnels for the dogs to run, play tag, hide and seek with eachother.
Then next to the back door, I put a tumbled bluestone patio. If they want to just go hang out on the patio and chew on hooves, they don't get dirty, dirt doesn't get tracked into my house because they wiped it off on the patio. My last female, when she was old I used to worry she was uncomfortable laying on the bluestone. Then I realized it was warmer and she must have liked how it worked as a heating pad on her old bones.