I am looking for a scent that is floral (gardenia or lilac) and long-lasting. In the past most of the fragrances I have purchased seem to lose their scent within a very short period of time.
Your nose does get used to your perfume within an hour so if you're smelling it stongly after that other people maybe getting too much. But if you have dry skin your perfume will disapate faster. So use a bath oil or oil wash like Johnson's cocoa and shea butter oil wash, or Nuetrogena bath oil, or my favorite Aveeno bath oil (it smells like almond extract, yum). As for scents that last, Chanel and Tom Ford are ones that stay with you. Choose one that is eau de parfume, it has the most essential oil to alcohol. I like to do the same trick with the perfume in my hair, I spray 2 squirts on my brush, let it dry a little and then brush. Good luck.
It may just be how your body chemistry takes the fragrances as some of my own favorite fragrances just don't stay on no matter how much I apply!
Investing in a fragrance kit that comes with the lotions and shower gels is a great way to envelop your skin in the scent, and you can even spray a tiny bit on/in the hair to hold it as well. Here are some great scents that have a bit more musky, rose or tuberrose notes that can keep them lasting a bit more:
Dolce & Gabbana Rose The One
Bvlgari Omnia Coral
DKNY Be Delicious Fresh Blossom Eau So Intense