I believe there is an inking tool for everyone. Artists of all skill levels can work with it, and this is the main reason that ink is a well-loved, tried-and-true medium.
When I first started incorporating inks into my artwork, I thought ink drawings came in one form: black and white, pen on paper. While I loved how thin, black lines emphasized all the textures and details in my illustrations, I dreaded the inking process. I would start every drawing with an accurate pencil sketch before pulling out my fineliner pen, so scared that I would slip and ruin the whole piece. Ink was intimidating, too permanent, and unforgiving. Gradually, I realized that I was limiting myself, forcing my fineliners to behave in a hundred ways instead of finding appropriate tools to fit my needs.
Think simply. If the pen ink is too black, use a gray pen. If there is too much contrast between the ink and the stark white paper, try using toned paper or tint the surface with a light wash of ink. Research other ink mediums that are available to you and gradually build your inking repertoire. There are dye-based, pigment-based, alcohol-based inks, and more. There are special effect inks like metallics and fluorescents that can add an extra dimension to your drawings. Some inks are waterproof and some are not, but both can be diluted and used like watercolor paints.
Think about your art-making habits; they can affect what tool is best suited for you. For the artist on the go, fineliners, brush pens, and markers are convenient and portable. For the sedentary types, explore the world of dip pens and the many different kinds of nibs. What is in your price range? Expensive doesn't always mean it's the best, and a cheap price tag isn't always an indicator of poor quality. Do some research into art supplies.
Each ink and tool has its advantages and disadvantages, and every combination creates a different effect. If you happen to mess up, a little bit of acrylic paint mixed to match the paper's color can hide that right away.
There are many tips and tricks to make inking easier and less daunting, but there are no set rules to pen and inks. Some days, I'm a purist, and I want to test the limits of a single gel pen. Other days, I'm combining dip pen, brushes, pigment inks, ballpoint pens, and markers all within a single square inch of drawing.
Just as there are infinite ways to draw a line, there will be an ink medium or tool that could cater to any art style. What do you want to try using today?