‘Good Tango’ is very subjective. Because your idea of ‘good’ and someone else’s idea of ‘good’ are based on their experience, and a built (or created) appreciation for what you’ve been taught.
The Talking Cabeco/Mirada
If you’ve been dancing a little while, or for many years, at some point along the curve you’ve heard the word ‘Cabeceo’. Which roughly translates as a slight nod or nodding of the head (Cabeza) for the Lead to invite a Follower. The Follower’s side of that same invitation is referred to as a ‘Mirada’ (to look at, or ‘looked’). It’s an oddity that almost no one knows about the Follower’s side of the equation, that the Follower can ask for a tanda, employing the same methodology. It just has a slightly different name.