If you think that your story people need work here is what I do.
Also research/ create how the community that you are writing feel about certain this within modern media
I advise you to think about what you charter is like as a person there like, dislikes, I also would that describes them, there 16 personality type, then I look at the developmental stage they are at and think how got there. Then I think how forgiving they are, the temperment,there hope dream what they want in life, their fears, family, friends, living contion, if they were educated or not and if so where and what impact does that have on them? there flaws? what has been a big impact on there lives? I find a chacater sheet useful. Also If they are disabled them I will look how the disabilty effect that person day to day and how they get around it. Same thing if they are under opression for whatever reason. Then before I place them into the story I run them through rolyplaying situation (If you want some link let me know not sponsored through.) to get to know them and see if I have missed anything out of the charter?Then I design then bace their taste and how fabric make them feel. (do like soft clothing or jeans as an example) Do they have money to burn or are they just getting by? What are the customs with clothing and society at large. What the tempura of the place hot, cold, rainy, dry. Also I check for unconuscious bias and take it out of the charater if there is any.
Aslo ask other people and see what they think
here is my comic btw