I'd have to say a combination of these last 2 posts.
Blends - I look at the components and stay more towards what I know I like
Brands - first reputation of the brand / factory and then my experience with that brand
Recommendations / reviews - first of my fellow Cigar Aficionados and then the commercial reviews
Pricing / availability - gotta be affordable to smoke more than once and I prefer something that's going to be around (most of the time)
Hype / marketing - last on my list. I don't chase much but once in a while (usually the TAA releases) everyone likes to splurge