I pretty much just run across them, but if I'm over marking an existing scrape or making a mock scrape I only use buck urine in the scrape, and spray some forehead gland on the licking branch. I never use estrus anymore...just never worked. If you get a buck thinking he has competition in his area he'll be checking in on his scrapes more. For a mock scrape you need a licking branch above the scrape about 4-5' off the ground. On my farm the deer seem to prefer oak branches vs others.
Depends on the time of year and where I'm hunting. I create scrapes on my own property with overhanging licking branches. They usually do a great job fooling the young bucks. Once they start using them, the older guys will start coming in. I have several on my property and don't always hunt over them, but use them as a method to keep the mature bucks on my property for longer. Late October here in the Northeast is when I find it easier to find licking branches on the public grounds I hunt. Its just really tough in the summer when the leaves are on.