Two suggestions immediately come to mind. First, get an air horn and don't be afraid to use it. Other things to add visibility is a light bar with widely spaced lights, and somewhat more controversial, louder pipes. OEM pipes are just too quiet unless you are really aware of how to avoid being in a blind spot and invisible. That leads us to the next suggestion.
It helps to take the MSA advanced rider course. You can get some awareness coaching that may increase your margin of safety, skills and improve reactions to situations before they happen, and if they happen. I took one last November and wondered if it would be useful for someone who had been driving motorcycles a long time, and I wasn't disappointed.
Something that may or may not help, try riding with a group from time to time. Its a whole different dynamic, and has its own set of risks, but groups are very visible. If nothing else, you get together with riders with similar interests, concerns, and you will ride to some interesting places.