With my mare I put a longer lead rope on and dropped in on the ground [with my gelding I put it over his neck tho] then I told 'stay there' and point at her. Everytime she moved I made her put her feet back in the same spot and said 'HEY" firmly. I started out standing really close to her, now I can walk around and out of sight or go get her grain and she wont move. I also find that its easier to do some things [like pull her mane] while she's ground tied. She knows that when she is tied or on cross ties that she can move around a little bit, but when she is ground tying she's not allowed to move her feet. I love ground tying ! Since she has learned that rope on the ground means stay there I can walk and with out pausing drop her rope and she will stop and stand right there.