Hunting is a major aspect of Red Dead Redemption 2, and it can be difficult at times. Even if you're not hunting legendary animals, sometimes finding the right beasts for your needs can prove to be a challenge. Bait is a great way to augment your hunting, but using it properly is key - thing is, the game never properly explains how to do that.
It's easy to assume that bait is a magical make-animals-appear item. Placing bait would increase spawn percentages in a given area of effect, right? Wrong, actually. Placing bait has no bearing on animal spawn rates in game, nor does it affect any animals far away from the bait. What you need to remember is that bait doesn't come first.
Before you try and use bait to lure your target into a trap, you need to actually find the animal you are hunting. Only after that does it make sense to place the bait and use the cover scent lotion. This will lure the animal closer to your location, allowing you to catch it unawares from closer range. It won't, however, summon cougars out of thin air.
Potent baits have a larger range and greater effect on animals than regular bait. If you are looking for crafting supplies, berries can often be looted in the Tall Trees area, or in cabins. It is a common misconception that only blackberries are suitable for crafting this item, as any berries will do.
Potent bait, due to its range, can be used to attract prey you haven't tracked down yet. If you place it in open areas near the usual spawn locations of the animal you are hunting, you have a chance of attracting the beasts. You need to make sure you are downwind lest your scent gets carried.
It's good practice to find your hiding spot beforehand. That way once you've placed the bait you can go to your spot immediately without wasting time to find it then and there. Also keep in mind that the time of day affects how active certain species are. Nocturnal animals will, logically, be more common at night.
Note that some animals are simply less susceptible to bait than others. While potent predator bait may attract throngs of coyotes, boars and bears, cougars seem to be uninterested even in potent predator bait. Players have had greater success in hunting cougars by using their mount as bait instead.