On the stage with the performer are two folding chairs. These chairs might have been on stage all through the show. Perhaps they were used when the performer had members of the audience up on stage with him. Or the chairs can be brought onto the stage when the illusion is to take place.
The chairs are set up in the center of the stage, facing each other. They are about four feet apart. A heavy board is then placed across the back of the chairs. A person is requested to lie down on the board. This person can either be an assistant or someone from the audience. One of the chairs is then removed. The person and board appear to be suspended in mid-air. A hoop can then be passed over the person and down to the floor of the chair. The chair is replaced, the person is asked to step down and the board is then removed.
The action of slipping the board into the metal is a sliding motion, a motion easily covered by setting the board on the chair.
It would be wise to have the chair's metal bracket installed by a welder. It is also a good idea to the welder reinforce the slot in the board with a metal retaining plate. Usually the boards need to be quite strong, because the weight of a person on the board could break a board which is too thin.
I suggest using wooden chairs rather than the aluminum type. Paint the chairs a bland color such as brown. Make sure that the metal is painted the same color. The board can be a brighter color. I used a board which had the color and logo of a sponsor. If you don't have a sponsor you can probably use a well-known company by simply asking permission. This way the board looks more like a billboard than a specially-prepared magic prop.
Always remember, it is better to use props that look like everyday items than it is to use shiny brightly colored props. Misdirection works with the props just as well as they work in the presentation of the props.