Shopping for the right scent can be somewhat overwhelming. My suggestion is to take your time and don't try too many in one day.
Bring a little bag of coffee beans with you when you go shopping. Sniff the beans in between trying each scent. The beans will help to neutralize your sense of smell.
Have the sales woman spritz the sample on a blotter and take the blotter home. See if you still like the perfume after a few hours. This allows the true smell to develop. Also, there is nothing wrong with asking for a sample at the fragrance counter! So, if they have them, take one and try it at home before you buy it.
Once you find your dream scent, you might be living with it for a while, so you want to take good care of it. Don't store it in places of extreme temperature change or direct sunlight. Actually, the fragrance will last longer if you store it in the box it came in.
Lastly, a lot of people don't know this but it's best to apply perfume on slightly damp skin. Avoid rubbing your wrists together, it will crush all of the notes! Let the perfume unfold naturally. The best places to apply: you wrists, inside of your elbow, along your hairline and on your belly ( the heat of your body causes the scent to diffuse).