Scientists make predictions, and predicting the future is far more valuable than explaining the past. Ask a physicist what will happen if you fire a projectile like this in that direction, and they'll know. Ask Walter White how to make the meth blue and you'll get the right answer.
Analysts who come up with plausible explanations for what just happened don't help us as much, because it's not always easy to turn those explanations into useful action.
The practice, then, is to start making predictions. In writing. You don't have to share them in public, but the habit will push you to understand your instincts and to sharpen your ability to see what works (and what doesn't) without the easy out of having to explain what already happened.
I predict that the more you practice your predictions, the better you'll get at discerning where the science is.