Decoys work well. Not just antelope but cow and horse decoys, will get you much closer. I've also moved in as close as I can without being seen. I stop where the brush is high enough to somewhat conceal myself, and then grind my boots into the ground. The grinding must sound like a buck making a scrape, because if the herd buck can hear it, he comes running. I've had them come to within 20 yards, and just stand there and stare. My oldest daughter got her first antelope buck at about 20 yards when I used this technique.