I like seeing art that prioritizes clarity of reading, I like fonts that are big and legible enough to read on a phone without having to zoom in and out, and I like panel layouts that aren't confusing.
I like seeing skillfully drawn environments in a setting that supports the story.
I love a strong cast of diverse characters who each have their own motivations and personalities and aren't just stereotypes or cliches. I love seeing characters of all colors and backgrounds and sexualities, but that don't feel like the creator deliberately tried to throw one of every letter of the LGBT alphabet soup into their story to try and cater to every minority audience.
I love a good romance that develops over the course of a story that doesn't pop up out of nowhere or feel forced, and doesn't fall into some of the negative BL tropes.
I really love strong costume design for characters! A great, believable, original costume is chef's kiss to me.
And I like seeing all of that come together with a plot that is driven by strong character motivations, not by a series of random events that coincidentally happen to the characters.
That's just me though!