From a passenger point of view:

1. Try putting your rollaboard in the overhead bin wheels in or wheels out to maximize the number of bags that fit in the overhead bin.

2. When loading or unloading the overhead bin, try to stand in the aisle seat instead of the aisle, if there is no one sitting in the aisle seat. Standing in the aisle while unloading the bin blocks others from exiting the plane, which may cause someone in the back of the plane to miss his/her connection.