I go with naming a couple of dishes I'm trying to choose between - usually I ask for further details and gauge my choice by their reaction.

I do much the same with the wine list. I choose a couple of interesting (non-obvious) wines within a certain (always low) price range and then ask the wine waiter his or her opinion, or whether something else is better. Again, I can gauge what to do by what is said in the reply - ie do they know and love wine and understand the price point, or do they just want to get me to spend more, or push some plonk which obviously will be no good.