I'll take a slightly different approach here. Archery hunting hillsides and valleys I believe is different because your scent travels differently. In a valley in the cold your scent tends to hold tight to the ground and linger in the valley. Hillsides tend to see more upward air current movement as the air warms up in the morning then the reverse in the evening as your scent travels more downward as the air cools down. On hills try not to hunt the very bottoms nor the tops. Find the cuts/trails that come off the top down and set up about 3/4 up the hill on a good intersection of a couple of trails. Finding scrape and rub lines is a plus for rut hunting bucks.