Try to make them have characteristics that are unique and genuine. I've come across numerous people creating characters that are all generally the same. Same body type, same personality, same dislikes, same likes, same ambitions, etc. These make characters boring. Give them things that define them. Give them things that real people have that make you like them. Maybe strange fears or dreams or habits, maybe a dislike for a food that is generally titled as delicious. The more things that you add to make the character stand out and be unique will make it more liked and genuine.