 The first thing you want to do is understand the kind of crops you're going to spray, the chemical that you're going to spray, what rate you need to spray, the pressures that you need to spray at, your desired travel speed, and the drift risk. Make sure you read the label of the product and always consult with your agronomist. They're going to help you get to that right droplet size for the coverage that you need for the right efficacy for the product. It's also important to remember that tips wear out.