Always ride proactively, don't let things just happen. There are very few accidents that can't be avoided although sometimes **** happens.
Safe riding is a matter of planning and using your forward vision. Look as far ahead as possible, not just at the road you can see. If you're riding through countryside and you see a farm atop the next hill, think about what that might mean, mud on the road, farm vehicle emerging etc and plan accordingly.
Don't ride the racing line, ride the vision line. What that means is ride the line that gives you the best visibility ahead and any other traffi the earliest opportunity to see you.
Make yourself visible. Move about, moving objects are caught in the peripheral vision even if the other road user isn't looking directly at you.
Always ensure that you are able to stop in the space you can see to be clear on your side of the road. Pretty obvious but you'd be amazed how many people don't.
Always ride your own ride. Don't get sucked into riding faster than your ability allows. And don't get sucked into an overtake by a rider in front of you. Plan your own overtakes.
Get some advanced training. It'll make you faster and safer, you get more enjoyment out of your bike and you'll meet a lot of new like minded people. Read the police riders handbook, "Roadcraft", its available on Amazon, and practice what it tells you. Ride to "The System", (Information, Position, Speed, Gear, Action). It applies to EVERY situation and could save your life.
The best change you can make to any bike is the rider.