Follow the instructions for piping and you will get good results even on the first try.
Use a nylon and plastic-coated canvas bag. Disposable bags are good, but sometimes they split if you try to use them to pipe a firm dough.
For best results, use the size and type tube specified in the recipe. A smaller tube could crush delicate mixtures and cause them to liquefy or, if the dough is firm, may make it impossible to pipe. Conversely, if you use too large a tube, a soft mixture may flow through it too quickly and if the dough is firm the result will be gigantic cookies.