I haven't done anything really, but my friend installed red neons on his bike and he said at night time he feels MUCH safer.
(not his bike but looks damn close)
Also reflective tape is always a great idea.
As for heavy traffic, I guess the best thing you can do is just know how to stay out of people's blind spots. Always ride with your
high beam on!! during the day time, it dramatically improves your visibility. Also while in heavy traffic, don't feel afraid to beep your horn, rev your engine, whatever it takes for people to take a second to look at you and know you are there.