You are in a large city high-rise building. You only have one bar on your mobile phone yet need to make a call. The call won't go through. What is the BEST course of action in this situation?

Dropped signals frequently result from weak signals. You should assess the device's signal strength before making a call. If the signal is weak (for instance, there are no bars), change the location (drive out of the tunnel, get out of the elevator, step outside, etc.) and try again for a stronger signal. Keep the battery charged as much as possible because a low battery can impact signal strength. If something is obstructing the signal, waiting a few minutes won't solve the problem. Additionally, cycling the power off and on probably won't help. When your signal was weak, you most certainly wouldn't reset your phone to factory defaults!