Most Helpful Guy
This is very subjective and a bit hard to answer. I'll try and break it down into manageable parts...
1.) The first thing I notice: Generally, I see the eyes first (in a physical sense). Personality wise, I also notice if they are looking at me, having a hard time looking, or whatnot. The general look of a person is generally wholistic I'd say, meaning the physical judgement is done all at once.
2.) The biggest physical turn off: I'd say extreme weight is the biggest turn off. Now, I'm not talking about whether someone is skinny or average, but I mean like whether some is skinny/average or obese. I find obesity as a turn off. Can't help it.
3.) The biggest physical turn on: I find smiling to be the biggest turn on (Often paired with laughing). Like I find it really cute when a girl does what I call a "smirky smile." That is, like a small bit of smile accompanied by a chuckle. I don't know, I find it attractive haha.
4.) Biggest personality turn off: Boundless arrogance. Arrogance, from my experience, tends to really affect the person's actions and words on every level. True arrogance is a big turn off for me and will make me avoid the person. I think I've only met one person in my life who has a large ego but is still cool to hang around.
5.) Biggest turn on: Similar interests (esp. music). Now, I don't know how common this is, but I find it super attractive when a girl says she is into music or arts of some form (i. e. Plays guitar/bass/drums/an instrument, likes a similar band, draws, sings, paints acts, etc.). Not only does it show they have a passion, but having a similar passion gets my interest. If one ever wants to capture my heart, they should mention their love of music. On the outside, I'll be all like, "oh that's cool" nonchalantly, but on the inside I'll be all like "+10 POINTS FOR GRYFFINDOR" 😂
For a more comprehensive list of what I personally find attractive in a girl, I wrote it out on this question. It's a long as crap answer, so I'll just link it.