"Get a new haircut". This advice is the first one but it's probably just for guys with a full head of hair and ironically those guys look good even with messy hair. Most guys sooner or later will start receding or go bald so they keep their hair short because they actually want to look good given what they have.

"Skincare". This probably helps, I have no idea but does anyone think the average guy's problem is his skin? He had better skin when he was younger but he was still struggling.

Most women do put a a lot of effort into their looks but that doesn't translate well to men. Men don't have makeup or heels and unless he's good looking to start with, nice clothes won't make him look hot. The average woman can choose to look hotter, the average thin guy can't.