Kitty, what good clear suggestions. When this question came up recently my mind went blank on how to address the problem. The things you suggest are very similar to what I used teaching my dogs...and it works....most of the time. Kita is still young and impulsive and fast and has an excellent nose . However even she leaves food if I can get any cue, command, control, in place before she gets it. I remember several years ago walking with Zoomer along a city street. Without missing a footstep she turned her head a bit and came up with a Kentucy fried chicken carcass from in the leaves. I told her to drop, and she did as we both continued walking forward. Zoomer was very good with leaving food if I told her to leave it. And she was very good at finding stuff . I've never had my dogs to the point where they would ignore food on the ground when we were out someplace, but I also know I didn't work very hard to teach them that. "Leave it" and "Drop" were generally sufficient for my needs. Jo