I think I put a lot of myself in certain characters but not really in any way that most people who know me would be able to recognize.
For me my characters tend to have shades of different attributes I have (usually completely exaggerated for effect) or have traits that I wish I had.
One of my sillier comics (and probably the best example of a reflection of myself in my work) sees a main character who is an art school graduate who stresses out about her inability to get work in her chosen field, has low self-esteem, and no friends. (Kind of me except that I never graduated from anywhere and I was actually working in my chosen field when I was getting paid to draw this particular comic but it reflected my feelings at an earlier time of my life).
And then after she wishes for her pet cat to hang out with her and act as her friend and the cat becomes anthropomorphized she’s somewhat disappointed when her former-cat-turned-cat-boy-roommate excels in all of the things she can’t without even trying because he’s unburdened by the constraints of human convention. He wears all her cute clothes and gets compliments whereas she gets ignored, he goes to one art class with her and he draws more convincingly without trying, he’s not afraid of talking to people or looking silly so he makes friends easily. This cat character was based on the things I wish I were able to do.