I put this in, because it’s often said that readers prefer to keep company with characters they’d choose as friends in real life—so your characters ought to be attractive, likable personalities. Maybe it’s true, but I can’t convince myself to act on it.
I only care that my characters are interesting and colourful. I want to be able to empathise with them, but not necessarily like them or respond to them as friends. My protagonists are more often troubled than attractive personalities.
I’m not the person to give tips on this. Some other source of advice needed!