Mascara is one of my desert island beauty products (you know, the beauty product you literally can’t live without and would want with you if you were stranded on a deserted island because at least your eyelashes could look good if you’re going to be stuck there), and so it’s hard for me to imagine anyone struggling with it. I can’t even think about being without it!
Flatten your shirt as well as you can - make sure you don't have any seams laying oddly. Center the bowl an inch or two below the existing neckline. Make sure you're leaving an equal amount of space from the bowl edge to each shoulder.