Hovering a model helicopter is much like balancing a ball bearing on a sheet of glass. This is a half-serious helicopter joke, but it's actually much more accurate than people realize. If you place a ball bearing on a sheet of glass, and tilt the glass left, then the ball bearing will start to roll left and accelerate faster and faster.
If you tilt the glass right until the glass is level , then the ball will stop accelerating but will keep rolling at a constant speed. To stop the ball, you must tilt the glass right a little more until the ball slows down, then level the sheet of glass as it slows down.
A model helicopter behaves the same way. If you apply a little left cyclic and center the stick, the helicopter will tilt left and start to move left, and keep accelerating faster and faster. If you apply a little right cyclic then center the stick to level the helicopter, it will become stop accelerating, but will keep moving left. In order to stop the helicopter, you need to apply enough right cyclic so it will slow down and then level the helicopter as it slows down.
A common beginner problem is to overcorrect the movement and the helicopter will "pendulum" back and forth. This indicates you are either moving the cylic too far and/or holding it too long before centering the stick.
For the section we will divide helicopters into two types:
Helicopters with rigidly held swashplates
Helicopters with rigidly held swashplates hold the swashplate by at least three points so it is held rigidly in place. Helicopters such as the Hornet, Hummingbird Elite CP, ECO 8, Logo 10, etc are in this category.
These types of helicopters require small, delicate movements of the cyclic stick. Penduluming is usually the result of moving the stick too much.
Helicopters with "floating" swashplates
Helicopters with floating swashplates usually have a lot of slop in the control mechanism due to the floating swashplate. Helicopters with floating swashplates include: ECO/Fun Piccolo, GWS Dragonfly, Century Hummingbird V3, etc.
These types of helicopters are less sensitive to cyclic stick movement and are more easily controlled with larger, fast stick movements. These stick motions might be called a "twitch" for lack of a better word. Penduluming is usually the result of holding the stick too long in the pushed position.