Looks is a good part of it. But always remember it is only a piece of the puzzle. People use looks to determine what kind of quality of person is - but often it's regarded I think in the wrong way.
'Oh I need to look like a actor or be naturally handsome, etc.' - I think is a small factor compared to other 'look' factors.
Posture is huge. Shoulders up and back (not overly so). Head up, eyes up, chin up. Apparently can change rating by +2 out of 10. I notice it on girls as well, posture can change my outlook fast.
Cleanliness, taking care of your hair (head, facial), clothes are appropriate and fair fitting (vs raggy or dirty) - another huge one. Smelling clean (massive negative if not). Cologne not necessary (but can be a bonus if a light pleasant smell).
That's probably 60% of it right there.
For me, overweight can kill attraction. Some hold weight better than others, can even look good - but I see many an example where people can not look 'fresh' (like skin oily, and such)... And not saying skinny as a rail either or perfection. There's a definite fair range that is good.
People can define plenty of personality traits just from your looks alone. But the looks I feel most people think of (actor looks), and the looks that are most impactful (posture, cleanliness, fitness) are quite different. Because those last three - is how someone can define how healthy they are mentally, as well as the physical. It's self-evident, self-proving, and lends credibility towards saying that person has their **** together.
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Not to use myself as an example... but I was minorly overweight a few months back. Same weight as now, except fat --> muscle. I'm not talking huge, but I have shape now (vs a small bit before around my stomach). Started keeping my head shaved and well kept (vs balding pattern). This is where I think the biggest impact was (hair). So now I'm well kept, and visually 'clean'. Also helps confidence level.
Totally radical difference in approach by both men and women. Making friends much easier, flirtation by women, etc. It is not everything at all. But it helps your inner self as well.