While I'm far from a style queen, folk stating that a good haircut plus decent clothing are correct. I state this towards people who might be a bit insecure about their looks or lack confidence. Looking good and being attractive (as a male) is more than just being born with a hard draw and dreamy eyes. The right haircut suited to your face, and some nice clothing (not necessarily expensive, just stylish) will increase your "look" tenfold. And really, being able to exhibit a confidence in your personality goes miles too, and is something that doesn't show up in photos. I know plenty of dudes who, in photos, don't scrub up all that hot, but in person are charming, confident, and look like they're dressed in the right stuff, and it makes them all the more attractive.
Same can be said about anyone. I'm getting 4 or 5s here but I sure as shit don't let that eat away at me as someone "average". I'm better looking these days at 28 than I've been for the last 10 years thanks to some much needed weight loss (which is ongoing, so far lost ~20kg) and a wardrobe overhaul. Just ask some friends and family for tips, go shopping with someone if you're not confident in picking your own gear, and develop a style.