So, here's a principle: If you want to switch channels from blaming to discernment, start by paying attention to the feelings that arose right before you started the blame spiral. Find out what they have to show you.
Think of it as a process of retracing your footsteps. When you find yourself blaming—either yourself or someone else—ask yourself, "What was the feeling that started all this?" Be patient, because it might take a few moments to become aware of what the feeling was, but when it does, let yourself stay with it, focus in it. Then turn inside and ask, as if you were asking the feeling itself, "What perception lies behind this feeling? What is this feeling telling me?" The perception might be something totally unexpected—an insight into yourself, a realization about a situation. It might be that there's something you need to handle, something you've buried which is now surfacing through feelings of anger or sadness. You might realize that its time to act in a situation that you've been letting slide, or that you need to stop struggling and let a problem resolve itself on its own.
After you've sensed an answer, look again. Notice whether or not the perception you're experiencing feels clear, or whether you are experiencing another layer of the judging mind. The way to do this is to notice the feelings around your perception. If you still feel confused, angry, self-righteous, unhappy, over-excited, full of desire or any other hot or swampy emotion, you're still in judgment. In that case, ask yourself, "What is the root perception behind this? What does this feeling really have to tell me?"
This process of self-inquiry, if you stay with it, can give you practical solutions to questions about your life. It can also shift your inner state quite radically. Real discernment, I've always found, starts with the willingness to ask questions. If we keep asking those questions, we often get to the place where there are no answers at all, the place where we are simply present. Judgments dissolve in that place. Then we don't have to strive for discernment; discernment is as natural as breathing.