Since Aric has posted his number one rule of theology, and I've just posted my ideas about the importance of you starting points being clearly laid out at the beginning of any theology, I figured I'd better chime in.
I definitely agree with Aric's rule. I'm willing to disagree on details and to have my beliefs here challenged, but God has to be good, or else I'm out of the game. If I accept the possibility of some kind of god (which I clearly do) then I must accept some possibility of an evil god. I think I have good reasons why there wouldn't be one, but that's for another post, if ever. In brief, God is good, or God is not God.
I also want to have a rule that is something like science is very important. Science is a way of knowing about things we can perceive and experience materially. Ignoring it is really, really stupid. Our theology must make sense in the actual world where we all live. It cant' all be based on our arguments about our 'imaginary friends'. We do not dare have a flat-Earth theology, or a theology that posits a literal Hell in the ground beneath our feet, or one which posits angels floating above the clouds, because there are very good reasons to be certain that those things do not exist.
One specific area of interest for me is the science of mind, including philosophy of mind, scientific inquiries into consciousness and the various problems encountered there, and neurobiology. Theology takes place in our brains, and the more we understand about our brains, the better our theology will become. This means we need to be open to challenges leveled against our core intuitions and perceptions - things like "free will" and ego and our five senses, and how they seem to be partly what we think, and partly quite different than we would have imagined.
Another starting point for me is that experience is very important. Our theologies must conform to our experience - both because they will whether we admit it or not, and because our theology needs to actually apply to human life in discernible ways. What this implies to me is that everyone's experience is important to our theology, including atheists and Buddhists and Kalahari bush peoples and day traders in Manhattan and Japanese Shinto priests and so on. I am uninterested in niche theologies which only speak to a particular kind of Christian. I am also uninterested in Christian theologies which do not take seriously the experiences of non-Christians.
I am also an unapologetic, educated, enthusiastic and passionate pluralist. I've found it impossible to study religion and not come to respect it. I've found it impossible to meet people who practice other religions and not respect them. One way that respect manifests is to not assume they are tragically mistaken, that their reasoning and tradition and experience is chock-full of lies while mine is pristine. I just can't bring myself to do it, and I see no compelling reason why I should have to, as a Christian or otherwise.
Also, honestly, I meet Christians who appear to be practicing a different religion from me entirely, and I want to respect them too.
A last starting-point that comes to mind is my belief that our perceptions, intuitions and reasoning are imperfect, meaning the things we come up with are imperfect. If there are objective truths about things like religion, we will never, never know them, ever. Even if we could experience them we would not perceive them accurately. Even if we could perceive them we would not understand them accurately. Even if we could understand them we could not communicate them to others. And so on.
To be really blunt, I've never met anyone who claimed objective knowledge who didn't seem to be foolish in part and blind in part and deceived in part and correct in part - just like everyone else (I'd add some links, but I don't want to encourage them). Show me a perfect person, and I'll listen to their "objective" truth claims about religion. Otherwise, I'll assume you're all in the same soup I'm in, meaning grains of salt all around.
For the sauce on top of these things, I am an ardent pacifist, I have strong anarchistic leanings which I call covenantal anarchy, I have a harsh and often-inappropriate sense of humor, I live primarily in my imagination, I love J.R.R. Tolkien on a multitude of levels, I am not afraid of heresy (read: I am not afraid of ideas), and if I spend all of my time doing "churchy" stuff, I explode. I need a life outside of this stuff too, and I have one, and it is geeky and wonderful.
Addendum: it occurred to me after I wrote this that I should add my belief that what is true is also beautiful. I don't insist that this always hold true, but I am going to be drawn to truth statements and truth claims which make the world appear more beautiful, which are elegant to contemplate, and which appeal to my aesthetic sense. Ugly truths, for me, are surface truths. They are the fodder of stand-up comedians and cynical bastards like myself, but I think that ugly truths are painful to hear, forcing us to either laugh or cry bitterly, because they are incomplete. They leave one hungering for what is beneath them. At least, that's my take on it.