Piping is making designs with whipped cream, buttercream icing, royal icing, chocolate meringue, whipped ganache, and creamcheese, when squeezed from a filled pastry bag fitted with a tube, a parchment cone and, even a plastic bag or squeeze bottle!  This is done onto desserts such as cakes, cookies,  gingerbread cookies and houses, etc. 

REUSABLE OR DISPOSABLE PASTRY BAGS: When decorating with a filled reusable or disposable pastry bag, fitted with a tube, one hand is used to establish and steady the pastry bag while the other squeezes to release the icing. Using a parchment cone involves other techniques.

Before piping a design on a whole cake or cookie, practice  your design, either on a flat surface, such as a piece of waxed paper or on an upright cardboard cake round to get the feel of it. Practice takes time; it took me awhile to get the hang of holding the pastry bag properly. You can prop filled bags tip side down in a tall glass when not in use or on its side. 

A right-handed person should always decorate from left to right. A left-handed person should always decorate from right to left, except when writing. When decorating a cake on a turntable, work from the left at 3 o'clock, downwards and rotate the stand clock-wise, every couple of decorations. For flower making on a flower nail, turn nail clockwise in right hand as you pipe petals using the left hand.  

The way your decorations curl, point and lie depends not only on the icing consistency but also the way you hold the bag, move it, as well as pressure applied. Before starting, make sure the cake has cooled and/or the outside frosting has set before piping, if applicable. When not in use, store properly.

Different shapes and types of decorations require different consistencies of icing and buttercream -- stiff, medium and thin. If the consistency of your decorating icing isn't exactly right, your decorations won't be either. Make sure that your frosting is free of lumps that can be caused by sugar or shortening. Royal icing is thinned using glycerin or corn syrup. It can be stiffened by adding powdered sugar. Taking in or out of the refrigerator will harden or soften buttercreams.

In a beginner class it is easy to teach the three consistency rule, but in the real world cake decorators work with one....maybe two consistencies of icing. Over time you will develop a like for a certain icing. It will feel good in your hand, smooth nicely on the cake, and you will be comfortable decorating with it. Yes, perfect leaves are made with a thinner icing, and perfect roses are made with very stiff icing. 

To test the consistency of the icing or buttercream (recipe): In the beginning-----learning how to tell the perfect consistency----you can make a stiff version of icing and pull about 2 cups out, then thin the rest to a more medium/stiff. That way you have the stiffer for roses, and the rest for the rest of your decorating. Or, pipe a small amount or take a small dollop and place on a work surface with a small spatula. Then lightly place the metal spatula on top of the icing and lift it to form a small peak. You can tell the icing consistency from the size of the peak formed.

Sometimes when piping icing, you get lumps. There are some things you can do: 

1. Make sure you keep your icing covered at all times
2. Push icing through a fine sieve before filling the pastry bag
3. Put a piece of CLEAN nylon stocking over the end of your coupler (you have to use a pastry bag for this one). Then place your tip and coupler ring over that. The icing will have to be pressed through the stocking before it reaches the end of your tip, and will remove the lumps.
4. Make sure your powdered sugar is stored in a place where it won't get moisture in it. This often times is the cause of the lumps.

Holding a pastry bag and piping designs has to do with both the angle its held in relation to the work surface and the direction its moved in. If right handed, your right hand holds the pastry bag and applies the pressure, to force the icing through the tip, while the left hand helps to support and guide the bag.  

When you hold a bag, it feels as though you are holding a football or a javelin. Start by holding the bag in the V of your right hand, if right handed, between your thumb and index finger.  

Place the remaining three fingers on the side of the bag. When you pipe the icing, squeeze out the contents from the side with your fingers, while your thumb presses from the top. 

Steady the front end of the bag, with the fingers of your left hand to support the weight, and to establish direction of the tip. Using the index finger and the finger next to it, touch the bag on the side or underneath towards the tip of the bag; whatever works best for you. Remember that it's important to be able to apply pressure with all your hand. The left hand guides the bag. 

When you hold the bag at a 45 degree angle to the surface, you can sweep out a circle with the back end of the bag by rolling your wrist and holding the end of the tip in the same spot. (If you do not have a bag, try it with a pencil). Pretend that the circle you formed in the air is a clock face. The hours of the clock face correspond to the direction you should point the back end of the bag.

Sometimes instructions will tell you to hold the back end of the bag pointing to the right or towards you. Left-handed decorators do things differently. Hold the decorating bag in your left hand and guide the decorating tip with your right hand. If the instructions say to hold the decorating bag over to the right, you should hold your decorating bag over to the left. 

The size and uniformity of the icing designs you are piping, are directly affected by the amount and the steadiness of the pressure applied when you squeeze and relax the pastry bag. 

The goal is to learn to apply pressure so consistently that you can move the bag in a free and easy glide while just the right amount of icing flows through the tip. Practice will achieve this control.  

To pipe with the right pressure, do so at whatever angle the design requires, over the top or sides of the cake, with the tip a little above the surface. Press firmly and evenly on the pastry bag (squeezing the top of the bag rather than the middle) and move the tip at a uniform speed and pressure. 

When you get to the end, release the pressure on the bag, stop moving the tube, and terminate the design in different ways, depending upon the design: for piping a border, end with a quick flick of the tip of the pastry tube, up and slightly backward. 

To pipe buttercream flowers, such as rosettes and roses, press the bag and when the frosting spreads around the tip of the tube, slowly lift the tube as you move it in a tight circle to make an upward spiral. Finish the rosette by releasing the pressure on the bag and sweeping the tip of the tube to the center of the rosette and up. 

TO PIPING 101