1. Christian. This is the most conscious one. As a Christian there is a requirement that any guy I date should be a Christian. I am not some kind of elitist - just practical. My life incorporates a lot of bible studies, church on Sundays, weekends away with Christian groups and all my life goals relate back to the bible. Non-Christian guys are tempting, some of them very Christian in their values systems without the associated belief system, but at the end of the day Christian makes life easier and healthier.
2. Blonde hair, blue eyes. Alright I don't tend to go in for full ice features, but somehow the guys I like tend to fit this description. Hair somewhere between blonde and that colourless brown. Eyes somewhere in the blue eye spectrum. As with most looks based preferences it isn't a conscious decision. Certainly I don't look at a guy and think 'Nope, hazel eyes, he's out'. Rather in hindsight these are just the looks I tend towards.
3. Height. Up the last year or so I wouldn't have claimed this one was a strict one. Excluding a certain guy who shall remain nameless (they are all going to remain nameless :-P) I tend to run a strict 2 inches above myself rule. Now this one is perhaps my most difficult to get around petty physical issue. I'm a 5'10" and not a slight build. I like the novelty of looking up into a guys face. I am thankfully not so tall as for this to be an unusual occurrence. Just the same, I don't like feel self-conscious as I get with most shorter guys or guys my own height. I get a little irritated by under 5'5" girls with over 6'1" guys - go find a guy your own height. (Alright I'm not THAT fussed.)
4. Aloof Personalities. This one was hard for me to explain in words. I am, without question, attracted to level-headed, aloof personalities. I'd say something like opposites attract - except it isn't even so simple. I seek personalities that reflect the part of my own personality I like. I am very scattered. Sometimes bubbly, sometimes quiet, sometimes all out insane. I like the quiet personality best - it is the safest, the steadiest. Consequently I like guys who have that personality - and what's more they do it better than I ever could. The downside is I've been freezed out by a guy or two in this aspect of his personality, you just have to accept that goes with the territory. The benefits to these personalities are the kind hearts (a potential subcategory but nevertheless a requirement) that mean you can take their words at face value. Thoughts are hidden but overarching opinions aren't. If they accept you they'll talk to you, if they don't they won't. It suits me.