This looking outside is all very well, and I entirely agree with it, but....
Fixed wing aircraft have wings in the way, either above or below them.
Microlights have a great big wing in the way, above them, and nobody can see them anyway.
Helicopters can't be easily seen anyway, and can't see behind them.
Gliders are white and hard to see, and even harder to avoid since they don't fly in straight and predictable lines.
We all have to navigate and change radio frequencies and so on, and 10% of the time with head inside is enough for an accident...if it's the wrong 10%.
Maybe what we really need is a reliable LARS, or even just FIS, in the crowded airspace around London. Something we can all use, or even that's compulsory. Maybe even just a dedicated frequency, with blind calls being compulsory. Not the situation as it is now where everyone talks to a different person, or simply doesn't bother to talk at all. It wouldn't be that expensive, and it might save lives. Lookout is far easier if you know what you're looking for and when you need to look.