A vacuum is created by air heated by fire in a glass cup placed flush against the patient's skin. As the air cools in the cup, a vacuum forms that pulls up on the skin, stimulating the acupressure effect.

The cups are roughly bell shaped with a capacity of about 4 fluid ounces. 8 to 12 cups are applied to the subject's back in two parallel 'vertical' columns, midway between the spine and each edge of the body; cups within each column are placed four inches apart measured from the center of the cup.

There are several ways of heating the air in the cup with fire:

1. One can swab rubbing alcohol (minimum 90%) into the bottom of a cup, then light it and place the cup immediately against the skin. The seal thus created extinguishes the fire by cutting off its oxygen supply, preventing the person from being burned. The smaller the amount of alcohol, and the quicker the flame is extinguished by application of the cup, the better, so long as there is no risk of the cups falling off due to lack of a proper seal. Some experienced cuppers prefer the use of kerosene over alcohol, claiming it provides better ignition and thus greater suction.
2. One can hold the cup inverted over a flame (e.g. a lit candle), heating the air within it, then place the cup against the skin. Care must be taken not to heat the glass itself. Even so, the person to whom the cup is applied will feel distinctly more heat than in the previous method.
3. One can ignite a flame with a small alcohol-soaked cotton wad resting on a small pad of leather or other insulating material that rests directly on the patient's skin, then place the cup immediately over the flame, putting out the fire. The quickness with which the flame is extinguished depends on the size and shape of the cup.
4. One can place the cup on the skin and gently heat the bottom of the cup with a flame heating the air inside, whilst leaving a small gap to allow air to escape. When the air is heated sufficiently, the gap is closed and the air is allowed to cool.

Methods 1 and 2 heat the glass to some extent and have a risk of burning the patient if not carefully executed. Method 3 risks the cotton falling off the insulating pad onto the patient's skin, and leaves the pad and cotton wadding inside the adhering cup which could be considered cumbersome.

Baby oil massaged onto the skin prior to treatment causes a better seal to form, making it possible to use this therapy with less heating of the cup. It is often possible to slide the adhered cup around on the skin, preserving the suction seal as it glides. Care must be taken not to move the cup over protruding moles, skin tags, scabs, etc.
Circular cupping marks one day after treatment

The longer a cup is left on, the more of a circular mark is created. The skin pores are more open, and the patient may experience a sensation similar to sunburn. An application of about 20 minutes is average, for the back; however this varies with the individual. In no case should the cups be left in place if the subject reports noticeable discomfort.