If the full-face mask has a removable snorkel, then the first step is to secure the snorkel onto the frame. Make sure it sits tight so there's no chance of water coming in through it. Next, you need to brush your hair out of your face. Pull it back and make sure that there's no hair dangling in the areas of your face where the silicone skirt will hit your skin. Put the mask on your face. Keep the straps in front for now. Make sure that the snorkel mask sits tight on your face. Pull the straps over your head and adjust them until the mask sits comfortably yet tight. Breathe in and out and make sure you get air. Make sure the skirt sits tight around your face and isn't squeezed anywhere. Now you're ready to put your head into the water. Enjoy your snorkeling views!