Not judging is both very hard and very easy.
Let's start with the very hard. We are all different, from our experiential backgrounds, to our upbringing, to our emotional resiliency, to how we are feeling that day, to... ad infinitum. This means that your perspective is not the same as someone else's, and someone may say something that seems legit to them but is absurd to you. Looking through our own lens it is very hard not to judge people. Judging people is often used as a coping mechanism, or a tool to build one's confidence by putting others down, however, it also is a destroyer of relationships and a sure way to be labeled "that guy" with respect to unhelpful judgments and contributions (see photo above).
As leaders, that is not at all what we want. Trust is a key component to leadership, and the ability to listen open and honestly (without judgment) is a critical trait. We use this particular trait in our Checkrides as an indicator of one's leadership ability. It seems so simple, but many people falter here; the question is why?
Let's go to the easy part of not judging. Action takes effort, be it through a pointed comment, or a smirk when someone says something you don't agree with. One of the easiest ways to not judge is to simply not act. Save the effort. Don't say anything. Don't give them a funny face. Just listen, openly, and without judgment. At this point you are probably thinking, Alex, come on, just because I don't show it, doesn't mean I'm not thinking it. True. One element of leadership is that ability to listen openly without judgment, and performing that is already an excellent step to building trust. The next step is compassion and empathy. We are all human, so no matter what someone does (or how absurd it seems) put yourself in their shoes, and have some compassion for their situation and how they got there. If you can do that, you might find judgment just falls away as you open road to "how to fix the situation" instead of focusing on "how did we get here?"
If you can do that, you might just find people begin to trust you. They'll know that they can come to you with anything, that they won't be judged for it, and that you can help lead them where they need to go.
-Alexander C. Cook MEng, MBA, PEng, PMP
Photo Credit: http://www.chilango.com/cultura/12-leyes-que-provocaron-risa-y-coraje-en-mexico/