Perfect piping!
As with any grand design, getting the foundations right is important for a great end result! In this case, before you do any piping, you'll want to be sure of two things: that your meringue is the right consistency and that you have the correct piping tip to hand!
The meringue needs to have been whisked to stiff peak stage, so that it is able to hold it's shape once piped. If you have followed the recipe above, then it should definitely have already reached this point, since we will have whisked the meringue at high speed for a good 5 - 10 minutes. If you'd like to check it though, run a whisk through the meringue to gather some of it up and flip the whisk upside-down; if there is a small spike of meringue sticking from the whisk that doesn't flop over, then that's the perfect stiff peak! Alternatively, if you're feeling brave, you can try holding the bowl of meringue upside-down over your head! If the meringue doesn't slide out and cover you in a sugary nightmare, then it's ready to use!