Important Note about Salt: Not all salts are made equal and cannot be substituted 1:1. If you are substituting table salt for kosher salt, you will need to cut the amount called for in the recipe by at least half.
Make sure that the florets are completely dry before tossing the olive oil mixture. Excess moisture can prevent proper roasting and lead to steaming instead.
Spread the florets out in a single layer on your baking sheet. Overcrowding traps steam, leading to mushy cauliflower instead of that beautiful caramelization and crispiness. If your baking sheet isn't extra large, use two instead.