If you do not own a black lipstick, then go for a deeper maroon shade to start with.
Use a thin lip brush to line the lips and fill in the color.For more precision, opt for a lip pencil. Starting from the Cupid’s bow, make a ‘V’ shape on the upper lip, and draw a line parallel to it on the lower lip as a guideline. Gradually join all the lines to outline the lips.
Using the same thin lip brush, fill in the color and intensify it.