Incomplete thoughts on Meta-Epistemology

On my 2-day, 900 mile drive (I'm no Borepatch, with his buns of steel...and besides, I have children and a wife with me)...I was thinking about epistemology (doesn't everyone)...and I realized I hadn't thoroughly justified my meta-epistemology (which is largely that of descartes).

Let's go then:  how do you decide where to start in epistemology?

Ignoring MY obviously correct :-) answer:  It depends on your goal...then as far as I can tell, you have a very few options:

• Start from sense-observation...draw concepts back to things you can touch...work forward from there...and hopefully fix the concepts that aren't "tap-able".
• Start from social epistemology...and then work to confirm/disconfirm.
• Trust another specific authority...and then run tests on that.

Where can one start in one's epistemology?  Are there other places?