Make a triangle of baking paper by folding the bottom edge of the paper across to the side. Cut along the edge. Make sure the paper is smoothly folded and use a knife to cut along the crease to create two equal triangles. Place one triangle with the longest side furthest away from you.
Take one corner and fold it so that it meets the apex of the triangle. Hold this in place and now bring the other corner around the cone.
The bottom of the cone should be completely closed.
Fold the points back on themselves to make it secure. You can also staple if you like.
Either snip off 1cm from the bottom of the cone and drop in a piping nozzle, or simply cut off a tiny end of the cone to pipe directly from the bag.
To fill the bag neatly, stand it in a glass. Spoon your chocolate or icing in carefully, making sure not to overfill.
Fold up to seal and your piping bag’s ready to use.