Motorcyclists are invisible. Never rely on others seeing you, ride as if they're an obstacle you have to navigate.
You can hide a whole truck behind the A-pillar of modern cars, let alone a motorcycle. At certain angles, human eyes have complete blind spots that we're not aware of because our brain filters them out. Motorcycles fit perfectly into those.
Never hover in people's blind spots. Pass quickly or stay back. Do not drive parallel with another vehicle. Goes for cars too.
When approaching another car perpendicularly (like an intersection), remember that humans lose depth perception because their nose covers one of the eyes. A driver literally cannot tell how far you are. Our usual proxy is the distance between headlights. Motorcyles have 1 headlight so this heuristic doesn't work, but we don't realize that it doesn't.
Maybe I need a bigger bike, the 2cyl 400cc is particularly invisible. ;)
Best one was a woman who cut me off doing her left turn. I high-beamed her and honked. She put her hands in front of her face and came to a dead stop in my lane directly in front of me. I was already braking before I honked. Nothing happened. I stopped wondering and just assume everyone is out to kill me.
It's a rule that also applies to bicycles.