Sawing Someone in Half
A classic generic trick with countless variations.
The Trick
In this illusion, usually the magician's assistant lies in a box, the magician then proceeds to saw through the person, often the box is then split into two halves.
How
The magician's assistant will usually need to be a good contortionist. The assistant will get into the box, protrude their head through one end and then contort themselves so that they are only in about half of the box. They will place some fake feet out the other end of the box. The magician then cuts down through the box, where he or she knows that there is empty space.
In more complex versions there may be someone else's feet through the end of the box, this may be done like this.
This one makes it quite obvious what is happening.