Don't have any cotton balls? You can use a few paper towels, q-tips, panti liners, pads, and tampons! Yeah you heard me! A tampon is just a suppressed cotton ball so it works! (Ive tried it and it works)
Too lazy to use a q-tip and clean up around the edges? Use some elmers white school glue around your nails and let dry. Repeat to build up 3 layers. Once dry paint your nails and let them dry. Once dry peel off glue! Simple as that!
DIY Nail dotting tools: Take a bobby pin and dip it in the nail polish. Take a sewing pin (the kind with the tiny ball on the top of it) and stick the end into an eraser off of a pencil.