Its nothing special. Put the dogs where they can bail off and go where there are hogs. The more you do it the better you will learn to read the dogs and the more hogs the dogs strike like the better they will get.
There will be false alarms like a young dog taking a trail at first. You just make them load back up and go at it again. They will get better... some get scary good. Its alot of fun and a good way to win post-hunting hamburgers or some thing.