I have a little technique that I've developed for ordering wines off a wine list at a restaurant. I've been using it for several years now with a fair amount of success* but caveat emptor: I don't pretend to be any sort of wine expert!
I'm not sure I can properly explain the full technique as there's a lot of gut to it, but here goes:
I'll start by skimming the whole section of whatever wine I'm interested in (Burgundy, Pinots, "Spicy Reds", whatever they call it), getting a sense of the price ranges and the vintages. What I look for is a slight discrepancy, like if there's something that's a bit older than its peers but whose price doesn't seem to be correspondingly high.
Here's a made up example list to show you what I mean:
Vineyard A 1999 $34
Vineyard B 2001 $35
Vineyard C 2003 $41
Vineyard D 1997 $39 ⇐
Vineyard F 2000 $40
Vineyard E 2002 $44
In the above example, I would order "Vineyard D". Thinking about this more, I guess what I look for is a wine whose age is below average (in the above list, the average "age" is 2000.3 but Vineyard D is 1997) but whose price is average or slightly higher than average.
As I said, the process has always been rather instinctual, but now that I'm trying to write it down I realize there may be a bit of a formula here. Going forward, I'm going to try and keep track of the data and see if I can get a better sense of it. In the meantime, you can try it out and see if it works for you.
One general note: I don't order many cabs, so I don't know if this works with Bordeaux or California cabs. It seems to work for Rhône varietals and we were very happy one night when we decided we were in the mood for a Burgundy and used the technique to order a 1° cru Côte de Beaune.
* I define success by a) that I and my dining companions enjoyed the bottle and/or b) the waiter tells me, "that's one of the best values on our list, how did you chose that?" or "how do you know that wine? it's exceptional for the price," both statements actually said when I've ordered with the technique.