It wasn't easy!!! Sylphide was a dangerous runner as some Malt puppies can be--given an open door, she'd run out into the street and want to play chase--it was all a game to her, and she had no idea how dangerous this was.
So, teaching her Stay and Stop were essential to her well being.
My husband helped with this one. We took her to spacious outside enclosed areas (such as the outdoor agility facility), and one would stay and hold her while the other walked away. The other would release her, but when she wanted to run, let her go, quickly say STOP and hold her down (gently, of course). We did this giving her wider and wider range, over about six weeks time, until she did an automatic stop and drop at the command. She had a very reliable STOP after that.
I used a different method for her Stay command. I did that by myself by capitalizing on her love for playing fetch. I refused to throw until she stayed--first for two seconds, then five, then ten, then as I moved away, etc... She is very smart, and very quickly figured out what I wanted. I could then graduate that command to three things:
Staying, period: on the grooming table, downstairs, at the door, with me, etc.
a Sit Stay or Down Stay for ten seconds or longer, which is a required agility exercise. She is very good at this.
an extended stay as I move away from her, even outside of her line of sight.
I think all our furbabies are different when it comes to what works for them in training. As a puppy, Sylphide simply wasn't food motivated, and she certainly wasn't motivated to please us (just herself). The one thing that really motivated her was her game/play drive: wanting us to play with her. So I used that to get her attention. Now that she has mastered a lot of commands, and is actually more treat motivated as she gets older, I find it very easy to teach her new things.
Of course, the fact that she has participated in agility training, which is complicated, has really helped with her training.