Train for poor weather, but avoid the poor weather.
Always carry enough fuel for all contingencies, plus a bit extra.
Pay attention to your preflight.
Don't ignore something that seems/looks/sounds different than normal.
Fly as high as possible.
Always have a way out.
Brilliant. I've taken the liberty of printing that if you don't mind and sticking it in the top of my flight bag so I see it every time I open it. I've also added 'QDM and 121.5 are there to be used.'