It's Friday the 13th.  So here are 10 superstitions for you to watch out for today.
The Black Cat
Don't let it cross your path.

Broken Mirror
7 years bad luck if you break a mirror.

Whatever you do, don't walk under a ladder.

Of course the number 13
Buildings don't have 13th floors, airplanes have no 13th aisle.  You get the idea.

The Black Crow

Knock on wood

Don't open an umbrella in the house
Maybe it's more of people not wanting to get water in their house.  Maybe there is something to it.

Break a leg

Fingers crossed
I'm at a loss on this one.  But some people swear by it.

The wishbone.
I just always thought it was fun on Thanksgiving.  Wishes do come true.