During a recent flight in a C-152 we experienced a minor instrument panel fire. (See post in Hanger Flying: Know Your Emergency Procedures and Practice Them) This flight ended safely and we were able to make it home all in one piece, but there were some things I learned from that flight about taking passengers on flights. They are not always as prepared for the situation, as you should be.
Being a confident and proficient pilot, I was not scared or worried during our "adventure". I preformed the checklist items from memory and got us to the ground quickly. A fire is serious business but it should not be so distracting that you, as the pilot in command, can't fly the plane.
Passengers on the other hand are not always cool under pressure. Most of the time they have little or no prior flight experience. They are not prepared for an emergency. Because they are unable to control the airplane they will most likely feel scared and will be trusting you to get them to the ground safely.
On our flight my mother was very calm even when the smoke began to appear from behind the panel. The only time she felt uncomfortable was when I had to perform a slip while landing at the airport. The slip makes you feel like you are falling towards the runway. When the situation is already tense, because of an emergency, the maneuvers you are use to and are required to perform may be very unsettling to your passengers. They have never experienced a slip, a steep turn, or a power-off glide, before and may perceive the sensations these types of flight maneuvers create as an increase in the danger of the situation.
If you find your self in a situation outside of normal flight operation, know that even-though you will be under a lot of pressure your passengers are even more worried than you are because they don't have any idea what is really going on. Be prepared to explain what is going on or at-least reassure your passengers. If your passengers are calm it will help you stay focused and will make you feel more confident. Being focused and confident can be the difference between making it onto the ground or the front cover of Aviation Safety Magazine.
Be Safe: Know what you will do when your beautify flight becomes an unexpected review of emergency procedures.