If you're an indecisive sniffer, or if you just want to wear perfumes for a while before buying them, samples are your best friend. A sample allows you to live with a scent for a while, and I think that's the only way to go. Unfortunately, though, samples are not always easy to come by — but if you go to the right places, you'll have the opportunity to try before you buy, as they say. Keep in mind, though, that this isn't a free-for-all; it's best to ask for samples of only the scents that interest you, and even then, I don't ask for more than two at a time.
Without a doubt, the best places to find a sample are Sephora and Nordstrom. Both are happy to provide carded samples if they're available. And if they're not, a clerk will decant a perfume into a small vial for you. This is how I was able to explore YSL Elle for a week before figuring out that I didn't love it. And it's also why I'll be going back to Sephora to buy Narciso Rodriguez for Her.
For more of my findings,
After Sephora and Nordstrom, Bloomingdale's was the next friendliest. When I asked for a vial of Agent Provocateur, a clerk gladly produced one and showed me other scents I might like. Sadly, I was unable to get any samples at Macy's, even after a few visits. Neiman Marcus provided a couple of samples, as did Saks. Unfortunately, I don't live near a Sears or JC Penney, so perhaps some of you can weigh in on whether you can obtain a sample there. (By the way, the image used here is of If, which I tried yesterday. It wasn't for me, but — hey, if you're interested — Apothia offers samples through the mail for $5.)