Great questions! I don't have definitive answers, but I will be happy to share what I have learned/read. I am sure our resident perfume experts will be around soon to correct any misconceptions I have.
Would this fragrance be for you to enjoy or for someone else? My "audience" always affects the way I wear fragrance, such as how much and wear I place it. If it's for my enjoyment, it goes on wrists and chest, and I apply it pretty liberally. If I will be in public or it's for a romantic tryst, I will apply it much more subtly, so the person cannot smell anything unless they are within inches from my skin.
When I layer, I have noticed that the different formulations of the shower gel, powder, and fragrance all have slightly different fade times, so the effect can be quite subtle and luxe if I do not overdo the final act (perfume). When I use Chanel or Prescriptives products, I wash all over, power anywhere my body heats up naturally--plus a bit to neck and chest--and then I generally choose the lightest fragrance (EDT or EDP) and I use the air-spray method (see below).
With spray bottles, the scent lasts longest on me if I spritz the air in front of me and then walk through it. After doing that, I could get into a closed car full of people and (unless someone has chemical sensitivities) no one would be bothered by fragrance overload. Since I don't get into the clown car often, I usually just spray wrists, backs of knees, and cleavage so I can enjoy the fragrance, but when I spray the air, my fragrance lingers on wool sweaters and scarves for a much longer time (weeks). I don't really give two hoots if anyone at work thinks I smell good (in fact, I prefer that no one knows I m wearing perfume since it has become impolitic). I have always received the most compliments from Calyx and Hemes Eau des Merveilles, where I've been told I smell so clean.
When I use pure parfum (my first choice in winter), I do not apply it with my fingers, because I do not want oils from my fingertips or even epithelials transferred back into the bottle. I use the stopper to apply the fragrance to pulse points (throat/carotid, behind ears, temples, cleavage, wrists, inner elbows, and behind knees--and sometimes ankles), and then I wipe the stopper clean with a soft cloth, which I then toss into my lingerie drawer.
After I apply fragrance, I never rub it in. That is, I don't spray one wrist and then mash the other wrist into it to transfer the excess. I spritz or dab and let any alcohol evaporate. I do not dress until the perfume has melded into my skin, either. If any oils are sitting on my skin still from the pure parfum, I might press/roll it into my skin with my fingertips.
Finally, I have read that after four days of wearing the same fragrance, our noses adapt and we can no longer smell it (which might be one reason why some women wear so much perfume). So if you wear fragrance so you can enjoy it yourself, rotate your brands around every 3 days or so.
