Every location is different, since animals are creatures of habit. They tend to create a habit based on the area. The best way to determine this is with game cams over period of time. I usually set up two or even three cams in a prospective active area and if at all possible set up timed bait feeders to force them into a time I want them to be there.
I set up one cam to cover a larger area, however not all cams are sensitive enough to pick up movement from a distance so choose wisely. Another cam set up covering the bait site or suspected gathering area, these can be of lower quality cam since they only need to detect closer shots. Finally potentially a third cam to cover entry/exit game trails if they are out of view from the other two cams, this will tell you when they enter the area and how long it takes them to get to the harvest site.
I have found that depending on the hunting pressure hogs get they may come early morning, late evening, or only under the cover of darkness. Your cams will tell you what that group is accustomed too and if baited long enough without hunting pressure you can force a nocturnal group into the daylight with carefully timed feeders.
Once your location is dialed in, it comes time to harvest. Try to pick out the leader or alpha, that is the one whom leads the group and if you take that one out first the rest will stick with learned habit until another alpha is established. If you can take video of the bait site the alpha will be the one pushing the other around, pretty easy to spot but only under video or actually watching them. Give the grounds a week break or more and take the alpha again if you can determine which one it is and if a new alpha was established. If you repeat this method you will be able to take one or two pigs a week or two like clock work, because they are always in a state of confusion and just stick with their learned habits. Eventually they will catch on, then it start over again.
Ideally if you have two or three sites set up you can alternate which site you harvest from, which will decrease your chances of them catching on. Generally the same group will visit all of your sites and with your recon you know how many are in the group. Also sitting and not harvesting can further increase your chances when sitting to harvest, since you put your scent in the area without disturbance and they don't relate your scent to a loud noise.
Lots of work to dial this in, but well worth the effort in the end.
