Women in uniform. Police, army, hell, even letter carriers!
Women in eyeglasses
My wife wearing one of my dress shirts
or
wearing a baseball hat with her ponytail sticking out the back.
Gets me everytime!
Collar bones.
I don’t think anybody (so far) has mentioned clumsiness, but I’m glad you’re trying. 
Slim but well-built guys in tight black T-shirts, black kilts, and combat boots. (This is, or used to be at least, one of the common outfits for some of the groups I used to hang out with.)
Well defined male forearms.
Guys being gentle with animals, particularly cats. Not all syrupy and “Ooh, aren’t you kyoot!!” but just treating them gently, holding them, etc. Double points if it’s a kitten. This image just puts me right over the edge. 
I concur. When our office was robbed, the female cop who responded was totally hot.
Also small women with giant dogs. Like if you’re 115 lbs and own an English mastiff or Burmese mountain dog.
Quiet down, or I’ll smack you with my forearm while fixing my guitar, and shaving.
And being nice to cats, I already do that.
I was almost with you until you mentioned the cats. I hate cats.
Women who wear a hair scrunchie on their wrist when they aren’t using it.
Guys in kilts. Especially with boots; the utilikilt look mentioned above is my special weakness.
It’s my freebie ‘Ok, go ahead and look’ when the sweetie and I go to Highland Games. 
(He gets to look at corsetted boobs, so we’re even, right?)
The hint of cigarette smoke on a guy’s breath or clothes, or watching him smoke. Yeah, I know it’s cancerous and I’d never smoke myself, but damn, it is sexy.
Also, guys who play piano or sing or do anything musical, really, especially if they’re talented. Bad karaoke isn’t much of a turn on, but hearing a sweet serenade is heavenly.
Women wearing clogs, especially with jeans.
-Tattoo at base of neck (although I don’t like tattoos on women anywhere else).
-Sucker for a good ponytail, but the kind that are higher up on the head.
-A flat/small-chested woman who is confident enough to just be flat/small chested, and doesn’t try to hide the fact or fake anyone out with bras/accessories to make them appear larger.
it ain’t hot sex without hot, moist breathing.
Chicks with a ponytail through the back of a ballcap.
Chicks who drive a jeep, truck or suv.
This. And this.
Tiny chested checking in.
Just want to say this: sometimes I wear a push up or padded bra only so my tops will hang right. Certain shirts just look… wrong otherwise, and may gape open. I am not trying to fake anyone out or pretend that I’m a C-cup when I can barely fill an A-cup.
I also have no compunction whatsoever about going braless because the advantage to having small boobs is that I will still be perky, even when I’m 90. 
Women with masculine hobbies - collecting things that don’t have to do with the home and aren’t cute.
Old joke -
Guy sits down in his seat on an airplane to Omaha. The woman sitting next to him is moderately attractive, so he strikes up a conversation.
He says, “So why are you heading for Omaha?”
She says, “There’s a treatment center for my special form of addiction. I am a nymphomaniac, but only for Jewish men, and cowboys.”
“Very interesting”, the guy says. “Allow me to introduce myself - my name is Tex Obramowitz.”
Don’t forget to tip your waitress.
Regards,
Shodan