1- Monster can't look at them or they'll burn your eyes out.
2- Heinous, Busted- Needs plastic surgery.
3- Plain Ugly- Someone who was born ugly.
4- Below Average/Unattractive- Someone you'd never go out with.
5-Average, could be slightly unnatractive, someone you wouldn't look at twice.
6- Barely Do-able, wouldn't date them, but they can look OK if they try hard, also wouldn't look twice.
7- Cute- someone you wouldn't be ashamed of, I could settle for this but at the same time I would be thinking I could do better.
8-Generally Hot/Good Looking- definitely datable.
9-Super Smoking Hot- People you don't see in public often and most likely out, of my league
10- Perfection- dosen't exist but someone can and definitely out of my league
IMO the 1-10 scale will only apply to you/yourself. e.g. If I saw a guy and thought he was really hot I would give him a 10 because he is exactly my type. But in reality he's probably only an 8, he could never be a model he's attractive to most or many but not to everyone.
Another point it how attractive the person rating actually is, you can't expect a 2 to rate anyone above 5 because to them everyone above that would probably be attractive. In the same way you can't get a 10 to rate anything below 6 because they would probably think anything below that is ugly.
People say they would go no lower than a 7, but could a 7 to you be a 6 to me?
Beauty is in they eye of the beholder, the girl that likes you won't think of you as a 6 or 5 but probably a 7 or even an 8.
If I am just walking by, hardly anyone gets a second look unless they have on a cool shrit or are doing something I can immediately relate to. If it is a friend or someone I know/interact with regularly, then what gets the second look is personality. Is he confident. Do we relate well. Is he being a douche. Do I feel like he is a creeper. Also, keep in mind girls hardly pick the guys out; we have vague standards that we kind of want met, but if a guy shows interest in us, he only has to meet some of the standards. Rarely will we be the ones picking the guys (actually asking out; we obviously pick them and try to flirt and show interest but it doesn't always work).
A lot of the time your immediate number isn't just looks, but presence and confidence. Like is he sitting quietly in the corner or having fun and being outgoing? Your more permantent number takes a little while because girls count in things besides looks. I notice 1-3 for being so awkward and if I find out they're nice I'll go out of my way to be nice and give them attention. I don't usually notice 3-5 and 6-10 I do.
At first it's actually more of how interesting you are. You don't have to look like Jude Law to get a second look, but that's one of the things that does. Physical looks aren't the only thing that gets you noticed. Looking slightly better than average (clothing wise) and being surrounded by girls WILL get you a second look. They'll think, "what's with that guy? What does he got?" Another is just generally be surrounded by a group of highly valued individuals such as the star QB, the girl called THE HOTTEST of the school, a very attractive librarian, i.e people who they themselves get second looks. This means that looks aren't the only thing that girls literally look at when they see a guy, they see your company, your level of confidence, how fun you are, your style, and a whole bunch more. The first look delves greatly into who you are. OH! you can also wear an interesting piece of clothing, an example is like me wearing my white jeans, it turns heads. Or even an interesting object like I don't know a rubik's cube. But remember, all of these things voice your character at first glance, this is why guys strike out; they don't present a good enough character to even approach.