Things to think about ! " Are you fit to fly"
Think about controlled airspace where is it and is it active,where can you operate safely.Most sightseeing tours operate near the ground and pilots can easily be distracted so think about what must be avoided.
A good idea is a briefing to your passengers regarding the safety features of your aircraft, keeping hands and feet clear of controls and in the unlikely event of an emergency how they can help.Let them know that you will not make low passes over people or places of interest on the ground as it is dangerous and unprofessional.
Brief them on a "Sterile cockpit" at the appropriate times so no distractions for the pilot, they can also be an observer for other aircraft and obstacles.
No steep turns close to the ground as not only can this be dangerous it will unnerve your pax.
Do a weight and balance for your aircraft and have all your admin paperwork in order.
With good preparation and some forward planning a joy flight can be fun for all so,
"GO OUT AND ENJOY YOURSELF"