Usually "the sky is a big place and the chance of two aeroplanes being in the exactly the same place at exactly the same height at exactly the same time" keeps us safe from this sort of tragedy. But in areas of heavy traffic, sometime's it doesn'
Agreed, but there are things we can do that may mitigate the risks even if only to a very small degree but every little bit helps, things like making yourself easier to see, I notice that a local flight school have kitted out their fleet with LED lights, yes they are not cheap but in relation to the other costs of flying like fuel, maintenance landing fees etc it really is a reasonably priced modification especially for non certificated aircraft the options are endless for lightening yourself up like a Christmas tree. PCAS systems have their shortcomings and will never replace the Mark1 eyeball but I use one and they without a doubt enhance your awareness of some but not all nearby traffic. Also, if you jump in your plane and there are several bugs splattered on the windshield get them cleaned off before the flight, I think you subconsciously reduce your scan and ability to pick out distant traffic if your line of sight is dotted with bugs even if just a few. Running with all the lights on in haze or reduced visibility, if the bulbs burn out before expected so what? Using proper self announce practices at uncontrolled fields regardless of if you know/assume you are the only traffic within 100 miles and start you common traffic announcements 10 miles or more out. I have flown into remote strips behind others who's extremely limited position reports make it like a game of hide and seek. And of course the fundamentals like clearing turns etc. And the old dependable, if have passengers tell them the first beer is on you if they spot a plane before you do.
Not saying any of the above would have changed the outcome in the tragedy in this particular thread and condolences to the friends and families.
Fly safe, little things may make the difference