Tramp out how? You'll find little terrain that you can alter. Many trails are faint (as in a novice will likely not see them when they're right there) despite nothing erasing them for ages. There's minimal vegetation already, nothing that will show to a passing plane.

I would consider a signal mirror a last resort as using one means you can't take shelter and will cook all the much faster. Smoke is more of an option but I would much prefer to save my gasoline for running the AC than for burning a tire. If I had some other fuel source fine, but it's such a low probability scenario it's not something I'm going to prepare for. My safety standards out there is never to be farther from asphalt than I can hoof it back if need be.