I throw salt over my shoulder, pick up and keep heads up pennies, pick up and give away tails up pennies (that is suppose to fix the "bad" of tails up), and knock wood ....my head usually being the most convenient wood available (when saying...I never get a cold...so it doesn't then happen.)

How much is tradition/habit, how much is superstition and how much just being silly???

The only time a broken mirror would bother me would be if it broke when I looked in it!