The eyes play a huge role in unique artstyles. There are so many... I'm not sure how I can help you much, but here are some tips.
1. Use highlights or sparkles if you want, but don't overdo it.
2. Draw the overall shape of the eye first.
3. Eyelashes can turn almost any eye into a female eye. Realistic eyes tend to have more visible eyelashes. But in anime, it is often exaggerated, like this:

In cartoons, sometimes there are no eyelashes at all! It depends on whether you draw a circle or oval and put a dot in it, or just draw dots for the eyes.
4. Realistic eye tip: The gap between the eyes should be big enough so there's enough space to put a third eye in there.
5. Don't draw anime eyes on an inanimate object. That would look really cursed.

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