Prep the veg like a legend. Scrub and dry everything. Peel the beets; peeling sweet potatoes is optional. Keep zucchini skin on.
Slice thin and consistent. Use a mandoline or a very sharp knife. Aim for 1/16–1/12 inch (about 1.5–2 mm). Consistency = even cooking.
Blot moisture. Lay slices on paper towels or a clean towel. Press gently, especially for zucchini (they hold more water). This step is the difference between crisp and meh.
Season smart. Toss each vegetable separately with a light mist or 1–2 teaspoons of oil. Add salt and chosen spices. Keep it light; too much seasoning burns.
Preheat the air fryer. 300–320°F (150–160°C) for more control. If your fryer runs hot, stick to 300°F.
Load in a single layer. Don't stack. Use a perforated liner if you have it. Overcrowding equals steaming. Nobody asked for steamed chips.
Cook by type.
Finish and crisp. Transfer chips to a wire rack. Sprinkle a pinch of salt while warm. Let them cool 5–10 minutes to fully crisp.
Batch and repeat. Keep going until all slices are done. Rotate between veg for fun and efficiency, IMO.
Optional pro move. If any chips feel soft after cooling, return to the air fryer at 250°F (120°C) for 2–3 minutes to re-crisp.