How can I make better decorations with a piping bag?

The piping bag is widely used both for making delicate decorations and for filling a baking sheet with cookies or choux pastry to put in the oven. The problem is that learning to control it properly takes a lot of practice.

How do I practice with a piping bag without first having to make some complicated preparation that I don't feel like eating (or making)?

An excellent substitute, very cheap and quick to prepare, is instant mashed potatoes! Instant mashed potatoes are very inexpensive and you can quickly prepare a large amount, and they have a consistency very similar to many of the creams and mousses we usually use in piping bags.

This way you'll be able to practice different shapes, or whatever technique you want to perfect, on a sheet of paper without it being expensive or tedious to prepare.