The most difficult thing about drawing this cartoon was deciding what the two people should look like. I ended up with two vaguely middle-aged white guys. But it took me a long time to get there.
For cartoons where the appearance of age/sex/race/weight has nothing to do with the point I'm trying to make, I try to vary the character types for diversity. I am a middle-aged white guy, so I fight defaulting to my own biases. But this can be a problem, depending on what the characters are actually doing or how they are behaving.