Preheat air fryer to 400° Fahrenheit. Once air fryer is preheated, lightly spray basket with neutral oil, covering bottom and sides of basket completely.
Add 1 bag frozen french fries to basket. Lightly spray tops of fries with additional oil.
Sprinkle salt or other seasoning over fries if desired, then place basket in air fryer. Air fry french fries 5 minutes.
After 5 minutes, remove basket from air fryer. Shake basket well to toss fries. If fries are not yet cooked to desired doneness, return basket to air fryer. Cook fries 2 to 5 minutes more.
After 2 to 5 minutes, remove basket from air fryer. Shake basket well to toss fries. If fries are not yet cooked to desired doneness, return basket to air fryer.
Repeat process as needed until fries are cooked as desired. Important: Pause cooking to shake basket and check fries every 3 to 5 minutes or fries will overcook.
When fries are as cooked as desired, remove basket from air fryer.
Transfer prepared french fries to plate or bowl. Repeat entire process with any remaining fries until desired number of fries has been cooked.
Serve fries hot with desired condiments and/or toppings.