Buy some temporary tattoo printer paper from an office supply store or craft store. Varieties come in the standard 8.5x11-inch size and are made for both inkjet and laser printers.
Open a graphic editing program and create a new file with your desired dimensions. Design the tattoo in the program or scan a drawing you created. You can also download a public domain clip art image and size it to the right dimensions.
Load the printer with the rub-on tattoo paper and go to "File" > "Print". Wait for the ink to dry. You can now apply the individual tattoos by cutting them out, pressing them face-down on your skin and rubbing the back with a wet washcloth.
Purchase printable sticker paper, which can be found anywhere craft supplies or stationery are sold. You can choose what kind of finish the paper has, such as matte or satin. Printable sticker paper comes in 8.5x11-inch sheets as well as blank label sheets, so choose according to the size and shape of your stickers.
Load the scanned image or public domain clip art into a graphic editing program and resize it or create your design in the program with the drawing tools. Create another document that is 8.5x11 inches and copy and paste the sticker images to it. Make sure to leave at least a half-inch of space between each image.
Print the the document. Carefully cut out each image, leaving about an eighth of an inch to a quarter of an inch of space all the way around the image.