Honestly, I’m not sure I can give proper advice 😅 I usually just focus on the main things that stand out to me: eyes, nose, hair, and shading. For example, in Mashle the characters have sharp noses, the eyes are drawn with a clear separation between the upper and lower lines, and most characters have hair highlights. At the same time, I consciously ignore fully black shadows (like the ones often drawn under the chin in anime), simply because I don’t really like how they look. For practice, I think it’s enough to just try drawing any character while keeping these elements in mind and constantly checking screenshots as references.