I don’t know who these three guys are and why they are posing for this portrait, but the challenge is a familiar one: to draw several characters with a variety of body and facial types, looking directly at “the camera”, with their eyes focused and faces symmetrical. This doesn’t sound difficult on the surface, and if you are sitting at the drawing table, it isn’t so bad. You have T squares and triangles and can pull lines across and drop them down to ensure that you are drawing things straight. But in sketchbook drawings, where you are holding the sketchbook in your lap, it’s hard to avoid parallax and “lean”. This drawing was heavily penciled with great care taken to get everyone drawn so they seemed to actually be looking out of the picture plane. And two of the three faces are pretty good. But the third has an eye flying away to the upper right at a rapid clip, and I feel like I’ve spent thirty years (at least) at this and I’ve learned nothing.
I still love drawing in my sketchbook, though.
(Note that in sketchbook world “appropriate dress” can mean a lot of things. A culture that includes sentient people with full hair coats is going to have to develop a pretty high tolerance for costume variations. Chewbacca doesn’t wear pants, and neither does the guy with the horns.)