One of the most difficult but necessary skills we need to develop is learning how to be judicious without being judgmental. And as a preliminary step to developing that skill, it's good to reflect on the difference between the two.
Being judgmental is basically an effort to get rid of something we don't understand and probably don't want to understand. We see something we don't like and we try to dismiss it, to stamp it out without taking the time to understand it. We’re impatient. Whatever we're being judgmental about, we just want to get rid of it quickly.
Being judicious, however, requires patience together with understanding. A judicious choice is one you've made after understanding all the options, all the sides of a question. That way your choice is based on knowledge, not on greed, aversion, or delusion.
The problem with being judgmental is that it's not effective. We try to stamp out things here and they go springing up someplace else. Being judicious, though, is more effective. It's more precise. We see what's really skillful, what's really unskillful in the mind, and we learn how to disentangle the two. Often our skillful and unskillful habits get entangled. The things we don't like within ourselves actually do have some good in them, but we don't notice it. We focus instead on what we don't like, or what we're afraid of, and we end up trying to stamp it all out, the good along with the bad.