Aside from the physical basics, the following are questions that may assist with an in-depth sketch:

-what is their motivation throughout the story- think of their motives at the beginning, middle, and end
-what are some traits you admire
-what are some traits that bother you
-what type of people do they like/associate with
-what type of a person do they hope/strive to be-does it always work
-what have they overcome in the past and how does that shape who they are today
-what are their accomplishments
-what are their fears
-are they popular or are they obscure
-do they play board games or sports
-do they watch movies or read or both
-would they rather eat a salad or a steak
-do they listen to music- if so what kind
-what type of a relationship do they have with their parents and/or family
-how do they treat others
-where do they live
-what’s their astrological sign
-what is their medical history
-do they have allergies
-have they ever been arrested
-do they have tattoos
-are they environmentally friendly
-do they have strong political views
-what is their spirituality
-are they gullible
-are they perceptive
-are they paranoid