Likeness is all about capturing the character. Try looking at the prominent facial features (big eyes, large nose, small mouth etc.) the try exaggerating them like
>>4323582 did
Take note that especially with characters from media who already have a known personality, try and remembering their personalities and form a character design based off that will earn you extra brownie points. Have a look at how shape and silhouette inform the viewer too. All of this boils down to character design really.
