Hello there! Sorry if the portrait looks a little different. The line quality may make it look slightly different, and I also changed the proportions a bit. I feel like the eyebrows and eyes aren't really what create that mischievous look. Instead, the shape of the lips and the mustache are what make the character look that way. So, first of all, I reduced the distance between the mouth and the nose, since there was quite a large gap. I also made the shape of the lips a bit longer to avoid making it look like he's pressing his lips together. In my opinion, this helps reduce that mischievous expression. As for the hairstyle, if the intention is for the hair to be styled toward one side, emphasize the volume on that side. The other issue is that the hair part is almost in the center, but if you look at references, the part usually starts closer to the side of the head. Reducing the volume on the opposite side also helps emphasize the hairstyle you're going for with the character. :) I hope this makes sense, haha. Hope this helps!