For me, first it's knowing when to stay put and when to make a move. I tend to get antsy after 30-45 minutes, and get the mentality to "go make something happen". Other times I'll have the confidence to sit for 2 hours in one spot sparingly calling to no avail.
Second, I would say losing my know how and questioning myself when they aren't talking but I know they're in the relatively area (within a quarter mile) of my location. Getting a lot better at this though as I encounter it more and more.