This video shows you how to use couplers for cake decoration using these steps:
1. Couplers usually come in two plastic pieces, a base and a ring. This system fits inside cake decorating bags or cones and allows you to use the same icing with different tips.
2. Choose which type of decorating bag/cone you would like to use. In this tutorial, a disposable plastic pastry bag is used.
3. Insert the coupler base into the chosen pastry bag/cone.
4. Find where the helical groove or thread of the coupler begins and note to cut there with scissors. (I rub the grooves with my thumb to leave an impression for a reference point.)
5. Push back the coupler base and cut bag.
6. Reinsert the coupler base and cap it with a tip.
7. To secure your decorating tip, screw on the coupler ring. To interchange tips, unscrew ring, insert new tip and secure again.