This is a great trick which is incredibly hard to figure out and works almost everytime (Everytime with practice). This trick is actually really easy to do even without trying it before but like any trick practice makes perfect.

Effect:

You get a number of object (I recommend something the size of CD cases) which are spread out in a line or a square, I recommend starting with 6 objects in a straight line from right to left. When you get better you could do this with a lot more objects in a square shape. The volenteer stands on the left side of you facing the objects. They hold out there right hand, which you then hold their wrist. You tell them to pick an object in their head, and hold there hand over the middle object. Tell them in their head to give you clear direction (left right and stop) to guide you to the object. You then move their hand correctly to the object they picked.

Secret:

Whenever they hand is in  the middle move it slowly a tiny bit left then a tiny bit right, see which direction it is easier to move their hand, whichever direction is easier that is the direction in which the chosen object is. After that they may move there hand themselves subconciously to the object, if not keep moving their hand in that direction until you feel more resistance.

When people are calling directions in thier head to move their hand, they will subconciously help you out and they wont even notice they're doing it.

Hope you like it, post comments and I will try to get more mind trick posted soon