Iron things. Especially scissors left out in plain view. Pins, knives, anything made of iron will frighten them, sometimes.
Clutter, disorder, stacks of things that haven't been sorted
Bells. Isome faeries like bells, but they are their own bells. If your cat wears a bell, or you have a very rude alarm clock, the noise may drive away the faeries.
Water. Many "psychic" experiences are attributed to a deep, hidden stream under a building. Some faeries are the opposite: They don't like to cross a stream, hidden or visible. (Then again, we have plenty of faeries who live in or near the water, so this isn't a firm rule.)
Looking them in the eye. It is said that you can gain control over a faerie, especially a Leprechaun, if you look him/her straight in the eye and hold that gaze