Wearing a good perfume is an etiquette in itself.
Giving off a good scent is a positive and gives your confidence a big boost, just like dressing well.
Some small etiquettes regarding wearing a perfume is to not over-kill it.
Wear a perfume which is best suited for the right event and according to season/weather.
A winter's perfume would give you nausea in summers generally and vise versa.
Many people spray perfumes directly onto their clothes, depending on the distance of spray and cloth, and quality of perfume, it leaves a mark, so be careful about that as it looks horrible to have perfume marks on your shirt, even if you're smelling nice, such marks would show that you have zero etiquettes on how to wear a perfume.
Pressure points is where you need to spray for maximum longevity.
Select your poison well, and you will definitely get great remarks and a boost to your personality.