I sometimes take small empty atomizers with me to Nordstrom, Neiman Marcus, etc. If I ask for a sample of a fragrance, and the SA tells me they do not have any, I say "Well I happen to have an empty atomizerwith me. Would you mind putting some in in it for me".
Usually they look a little surprised, but then say "Sure, no problem". I have not had anyone reject my request. Granted, I do not do this all of the time - just for a particular fragrance I really want a sample of.