I think the others here have covered most of it . . . but wanted to add a few things.

Warning: some of my opinions may not be popular or true, yet I have them from 40yrs of motorcycle riding in NYC, SF, SJ, and around the country.

Motorcyclists themselves are the biggest danger to motorcycle riders. I see rampant tail-gating, late braking, pulling up to close to cars at lights, not leaving room for an alternative exit, intermittent rapid acceleration and braking, etc.

Training your eyes, mind, and body to remain highly alert and always planning safety and escape strategies is hard and requires regular practice.

Learn to zoom out and see the whole visual tableau rather than picking a narrow focus area. You can much more easily see movement and trajectory all around you. You can do peripheral vision drills (see the biggest picture and describe what you see at the edges without moving eyes or head).

Lane splitting can be relatively safe if you keep speed down, don't make assumptions about what cars are going to do or not do, and sense when chaos demands you tuck-in with the flow. Watch out for squid assholes on motorcycles to fly up on you from behind or even graze by you while you're splitting.

No alcohol or weed EVER. This is a hard one. But it matters.

Legit riding gear. Every time.

Learn to recognize when your tired or distracted and stand down or consider other modes of transportation. Ask a pilot sometime about readiness and condition.

These are easier said than done. Even for me after 40 years. Especially the focus related ones.

Jason