We include information in our scheduling email to clients and real estate agents that outlines things that are required to help us fully complete our inspection and help avoid repeat visits which incur additional charges.  Those items are:
All utilities to the property be on
Clear access to the attic entrance
Clear access to the crawlspace entrance
Clear access to remove the electrical panel cover - move any shelving, vehicles, etc away from the front of the panel cover
Access to appliances such as water heater, furnace, air conditioner / heat pump
Unlock gates so we can easily access the back yard
Unlock any locked doors in the home
Animals be crated or removed from the property during the inspection to protect the animal, and all people at the inspection
We strongly prefer to complete our inspections at the appointed day / time, and do not like to charge for a repeat visit, so please ensure the home owner or occupants are aware of our inspection requirements.