When you catch yourself doing something superstitious, that self felt karma such as receiving bad luck for breaking a mirror or thinking food made you sick because you missed a stop sign a week ago, take a moment to ask yourself how one could possibly be connected to the other.
Don't be self-embarrassed to realize how foolish or silly it is. Address the "why" logically. Then decide if you want to change whatever specific habbit it is for the sole sake of not doing it.
You may choose to not change a habbit. Not because of superstition, but because you like it that way. Such as not having to learn a whole new contacts list order.
Recognize the difference between superstition and the OCD another poster mentioned.
Superstition: I should do it this way or bad things might happen.
OCD: I should do it this way each and every time over and over because It drives me nuts if it's different. (OCD effects more than just one task. It instead blankets most of your actions)