You know you're a good Catholic if...
... God tells you. Otherwise you're just guessing.
People say, "If liberals think you're too conservative and conservatives think you're too liberal, then you know you're doing something right."
And I think, well, okay, liberals find true Catholic morality too conservative and conservatives find it too liberal, but it doesn't follow that, if they find me similarly irritating, that I know I'm hewing to true Catholic morality. The Saints wouldn't be afraid to face me, but that doesn't make me the Redskins.
If I agreed with conservatives (and yes, for modeling purposes, "conservatives" and "liberals" are monolithic, homogeneous blocs) on some things they disagree with both liberals and the Church on, and I agreed with liberals on some things they disagree with both conservatives and the Church on, then liberals would think I'm too conservative and conservatives would think I'm too liberal -- and they'd both be right.
The people who say "...then you know you're doing something right" understand this, I'm sure. I'm just stating the obvious because -- well, mostly that's just what I do, but also to caution against both complacency and buying into the world's frames of reference.
True Catholic morality isn't "more conservative" or "more liberal" than some other position. It's true. Individual opinions (here I drop the homogeneous bloc model) may fall short of the truth in one way or another, but these modes of failure do not impose a character on the truth.