Simply spray on doorways, cat-flaps, window sills and prominent objects around the house.
To prevent marking if it already occurred, spray on marked areas after a thorough cleaning.
At home: Re-spray daily to reduce the likelihood of re-marking
During car journeys: re-spray every 4-5 hours (ensure your cat is away from the area while reapplying)
Always wait about 15 minutes before letting your cat near any sprayed areas
Never spray directly on your cat!
Never spray in the carrier if your cat is inside.