I can only offer my own perspective based on my own journey. You will ultimately have to judge for yourself what is applicable. I will try my best to keep this as short as I can.
First, I meditate a lot. This non-judgemental practice of gently bringing my mind back to my breathing helps me drop my judgments. It also helps me pay attention to the sensation instead of the thoughts. There are some types of meditations where I label my thoughts and emotions just to better understand my introspective private reality too. This is my, "truth."
Secondly, whenever I have a judgment of other people, I counter it immediately. I ask myself if their way might be better than mine. I go out of my way to look at alternative societies and ask myself what institutions or aspects might better the one I am in. I play with it in my mind and ask how life would be different. Having multiple perspectives is always good. The more lenses and perspectives you can get on your own life and how it could be different usually brings up new prescriptions for how to live your own life that you can choose to use or ignore. Studying philosophy really really helps with this too. In fact, a western philosophy crash course would be the audio-book... Sophie's World.
At least listen to that if you are not acquainted with western philosophy before tackling eastern philosophy. Eastern philosophy is fairly difficult to dig into. I have more sources on it if you wish. It's worthwhile though.
Third, sometimes I imagine or wargame how my life would be different in alternative societies or with alternative philosophies. Would I still value the same things? If so, then it's likely that such values are my internal truths apart from my society.
Fourth, a more scientific perspective on, "Our Own Truth," would be to figure out your OCEAN five-factor personality. Then, from there you can figure out what your core values are and how to use these to your advantage both internally and externally. The most scientific and accurate personality test would be the IPIP-300. Yeah... it's 300 questions, but you only need to take it once.
Then, you might want to read this to figure out how to deal with your personality and core values.
Finally... and I hope you guys don't hate me for this. However, I cannot recommend enough cutting out all of the news groups and journalists, and going straight to the source of science. Learn how to critically analyze a peer-reviewed scientific paper. The less layers of middle men you have to go through to find truth, the more accurate your knowledge of truth and beliefs will be. I link a quick paper on how to do this, and a very comprehensive course that anyone can audit for free.
So, I hope that together with the introspective and scientific, or perhaps just your selection of the pick, you can figure out your inner and outer truth.