To prevent a soggy bottom, blind bake your crust for the full recommended time until lightly golden and crisp. Avoid watery quiche by sautéing high-moisture vegetables (e.g., mushrooms or spinach) to release excess water before adding. Do not overbake; the quiche should be mostly set but still show a slight jiggle in the center when gently moved, as it will continue to cook as it rests. For dietary variations, consider a crustless option for lower carb/gluten-free, use dairy-free milk alternatives, or add extra cheese for higher protein.