How to make fluffy icing without using a hand mixer?

the above answer is good, but if you have a wisk it will take half the time. your arm will still feel like its about to fall off, but the wisk will incorporate air much sooner than a spoon. Add your ingedients to the bowl and start wisking away. you can make mayonnaise and even butter by hand, but it takes time.. prepare yourself for a workout and it wont seem that bad when after 5 minutes you haver a nice fluffy icing