For about 30 years I insisted it was best to approach a stand site from downwind and sit downwind of a whitetail feeding area. In the morning it seemed most logical because the deer I expected to see there would already be feeding, generally beginning shortly after 4 AM. They thus wouldn’t be able to smell me approaching or while sitting at my stand site. After years of noting the odds of seeing deer in the evening in a feeding area I had hunted in the morning were much poorer, it finally occurred to me why. Mature whitetails (whitetails that have survived two or more hunting seasons) almost always approach a feeding area (or bedding area) from downwind to avoid walking into a hunter’s ambush.
Most long-used feeding areas are ringed by a deer trail 5-15 yards back in forest cover, used by whitetails using their eyes, ears and noses to search from along the downwind side for predators or hunters hidden in the peripheries before exposing themselves in the feeding area. If you are stand hunting along the downwind side in the evening, it is almost certain approaching whitetails will identify you three ways: 1) by your airborne scents spreading widely downwind from your stand (whether elevated or ground level and whether using odor suppressors of any kind), 2) by your fresh trial scents (detectable by whitetails four days or longer unless it rains or snow meanwhile) and by your dark silhouette framed against the bright open sky over the feeding area.
Especially when stand hunting adjacent to a feeding area you plan to hunt more than once, it is therefore best to sit crosswind, morning and evening. To ensure, your widening, triangular-shaped scent vector does not spread downwind into the feeding area, sit where the wind is blowing at an angle toward your upwind cheek rather side of your head. Whether stand hunting at ground level or up in a tree, also sit 10-20 yards back from the edge of a feeding area where well hidden by forest cover. Because wind directions are changeable, be prepared to use two or more stand sites appropriate for different wind directions most common during your hunting season. Also use approach tails well away from edges of feeding areas so you will be less easily heard or seen by feeding deer while heading to your stand site, morning or afternoon.