To draw comic book lettering well, you should focus on clarity and legibility. Work on developing a unique style that suits the mood of your comic. It helps to practice regularly and get feedback from others.
You need to start with understanding the basic shapes and proportions of the letters. Practice different styles and get familiar with various tools for lettering.
Well, first, pay attention to the consistency of the letter size and spacing. Also, experiment with different pen thicknesses and strokes to add depth and character. And don't forget to study existing comic book lettering for inspiration.