I started using a Wilson Cell Phone Booster this past year. The side benefit is it helps with the signal for streaming for the occasional game when I'm otherwise out of range of towers.
Otherwise, I try to be very specific along with a map about where I'm camping and the route if I'm by myself which I avoid. In most of the Northwest where I camp, there are generally roads for fire fighting access even if there isn't anyone using them, so I try to avoid going off the roads. Seeing a few cars a day isn't really much of a problem for me and it's always a good idea to have a quick path away from fires.
