Making a double exposure image in procreate

Links for the images I used: Face https://unsplash.com/photos/ks7b752oXhw Birds https://unsplash.com/photos/SNJGZ619rEE Clouds https://unsplash.com/photos/v9bnfMCyKbg Cityscape https://unsplash.com/photos/qIhr98tTGko