The most common would include eye contact. Pretty sure its going to be at the top for MOST guys.
CIM probably #2.
Enthusiasm could tie with CIM.

For me ................ I LOVE blowjobs like this !
http://www.pornhub.com/view_video.php?viewkey=ph563588d98110a

Like said earlier.... everyone will be a little different.

I love eye contact and hearing kind of sloppy or suction sound.  Or if it sounds like the girl is enjoying it with yummy moans type thing.

I also love it when the girl has me to the base and licks my balls at the same time...... Only had two providers ever do that.... (I am average size).... but the DT with tounge on balls at same time is heaven for me.

edging is key to me.   work me up, then slow it all down, then back up...

all in to the base then licking balls is great.

combo of fully in mouth and out of mouth licking up and down shaft.

eye contact.

licking just the bottom of the tip.

balls completely in mouth while stroking shaft with hand.

shaft in mouth with just tongue action.

some suction sometimes... not all the time.

if you have the chest for it, some russian mixed in.

I also love the leaning up and making out for a bit, the back to the blow.

Oh Jesus, now you have me all worked up.   When is your next open appointment!!

(for me, slurping and moaning are NOT a turn on at all... feels like cheap porn)

Done by a woman!

Beyond that, wet and sloppy, cock and ball pleasure, DT, edging and milking, anything except i don't like my balls being bitten. Ouch, not for me.

Maybe I'll send you an audition tape to see if we're compatible😗

If you want to look up to see my reaction, that's hot, but eye contact isn't a requirement.  
You've always done a great "job" with me and it's nice to see you looking to improve.

RE:

http://www.spankwire.com/Deep-Throat-Dee/video134889/

While I certainly wasn't your "first," I did write your first review

and I remember that session (and the ones thereafter) quite well

Yeah I'd vote for some eye contact too, but not the whole time.
Lots of attention to balls but not all at once, better to break up shaft action, and usually best to do balls then shaft to maximize hardness.
No teeth, not sucking too hard, not too soft, just like Goldilocks would do.

Here's something I find a lot that can be annoying: Let me control my comfort/positioning!
Lying down on your back, while relaxing, can be the worst position for maintaining an erection.
Sitting up, or 45 deg angle can give much better control, and can always lie down near end of the bj too.
So many girls get upset if I sit up and think I'm not relaxing or enjoying, but only the guy really knows how he feels etc (hopefully).

I'm proud to say I've enjoyed Brandi's talents on a few occasions. The ending is as important as the beginning. Love the way she keeps her mouth on my cock till she's sure it's drained.

All the way down to the base and then back up but never let the head come out.

...unless they're some kinky fucks who enjoy that lol.

taking it all the way down past the tonsils. All the way down is a very rare treat, but I also love when a lady makes a  great effort at taking it all in.

Tounge action.  
Slow, firm, strokes of various depths from just sucking the tip to all the way in beyond the tonsils.  
Teasing the tip,  
Varying degrees of wetness...
CIM, and continue for a bit...  
Soft moans

I don't think you can go,wrong with anything that has already been mentioned.  We are guys for goodness sake...

Sitting in a chair with a sexy lady and her lips between my legs does it for me.  Being able to see the actions, stroke her hair and face, while she looks at me is a huge turn on.  Watching as she licks the underside of my cock from balls to tip then repeats that on each side is amazing.  I also like a woman who uses her tongue well.  Nothing like a warm wet tongue wrapped around and sliding up and down my cock.  Just the thoughts...  Last but not least, ya gotta pay ample attention to the balls.  And if you so choose, go ahead and give the taint a few licks or suckles while you're down there.  You'll get no complaints from me...

Nothing better then .....

Having a nice beautiful cock deep deep in my throat w/a tears balling up..... I love when a man makes me  tear up!

I was fortunate to learn the answer (for me) many years ago from one of the most amazing women I ever knew.

In the middle of focusing on licking my partner, she stopped me, and exclaimed, "This is the best thing ever!" As I looked up with a curious look on my face, she continued by saying, "I've had some amazing tongue before from both guys and gals, but you are the best ever. It's not about technique, although you are VERY good at this. It's about the obvious fact that you are taking such joy and pleasure in licking me! The smiles on your face, the way you look at me with longing, the passion you are showing, and the obvious pleasure you are getting through your giving... THIS is what I love more than anything."  

Then, with a wink, she added, "Plus... I can plainly see just how aroused you are just by doing this, and that turns me on even more!"  

Bottom line for me: It's not about how talented you are at "technique" (although I certainly appreciated talent!) It's all about the effect on my brain, and that starts if I know in my heart that you are taking genuine pleasure in giving. If you are truly into it, I'm all yours. Seriously all yours.