In my many years of icing toaster strudels I've developed what I consider to be an ideal technique. I will share it here, because why not.
Don't just rip the icing packet open and slurge it on the strudel in big streaks. Cut a tiny hole with a pair of scissors (or be careful and rip with your hand so that it's as small as can be), while still allowing flow of icing, and make really thin icing lines, covering the entire strudel. They'll melt from the heat and form a near-uniform covering over the entire strudel, rather than a spotty and non-uniform covering from a thicker flow.
It might seem silly since it's the same amount of icing, but the per-bite uniformity makes a huge difference, at least to me.