I’ve had the same problem, and I found that overcrowding the basket was one of the biggest reasons food didn’t turn out crispy. Leaving some space between pieces helps hot air circulate more effectively. I also try not to use too much oil, since a light coating is usually enough. Cooking times can vary between air fryer models, so I recommend checking the food a few minutes before the suggested time and adjusting as needed. For additional ideas and straightforward recipes, I’ve found
simpleairfryer.com useful. Keeping notes about cooking times and temperatures for your favorite foods can also help you get more consistent results.