C.V.
I don't have a hound, I have a Brittany/Border Collie mix. She's high energy too, and can be quite hard-headed. But she's super smart.
"Stay" is the hardest thing to teach, and many dogs struggle with it. Don't worry, just continue to work on it. Here's what we do...
For a Down-stay, I put her in a 'down' and then told her to 'stay.' I then started dropping little bits of treats in between her front paws, softly (but enthusiastically) praising her. If her elbows leave the ground, I stop treating her until she drops back down. You'll have to work on deference for this to work for you (PM me if you are not sure what this means).
I do this for about 5-10 seconds to start, and then release her by stopping the treats, touching her cheek, and saying "OKAY!"
That "OKAY!" means she is released from the "stay" and can walk around again. Let her walk around for a bit, toss a ball, whatever, before you bring her back to try it again.
I keep on doing that cycle, adding time on each training session. Each time, releasing her with an "OKAY!"
Don't try to add a bunch of time on in the same day. Your dog will just get frustrated. Stay consistent.
Then you start adding distraction. I'll start walking around her while giving treats, stopping if her elbows leave the ground. In subsequent sessions, I'll have someone come in with a distraction too, like bouncing a tennis ball. All the while, I'm giving her treats, praising her staying, releasing her with an "OKAY!"
If she gets up and ignores you, not giving deference when you stop treating her, there's two things you can do: Either you're going too fast and need to go back to a shorter timeframe and work on it....or you need to step up to a better treat. We use hotdogs as training treats for the REALLY tough stuff that she's being stubborn about, because she adores them (the dog trainer uses them too).
I don't recommend working on a down-stay or a sit-stay for more than a few minutes at a time. Switch it up and work on what she knows to keep her motivation up.
Best of luck!
C. Lee