How to choose a fragrance for someone else

       OK, so we know we love to buy perfumes for ourselves, spend hours dedicated sniffing & testing. Maybe trying and then going back (this is what I do::) ...but how can we choose for someone else.
If we want it to be fragrance oriented remember that Ambient aromas of somewhat high quality is always very an appreciated present. The "home fragrance" market the last decade has exploded and there are options so anyone can participate in feeling luxurious at home.
That said...When I assist people buying for somebody else this is one possible approach.
Take a moment and think about the person. You can scan for immediate reactions you get when thinking of that person. For example a color, how they dress the music they listen to or...how would you explain their character. Are their features made up by warm or cool colors? 
Ex. I am buying a perfume for my friend "Salomeh".  She is originally from Iran, but grew up since a very young age in Scandinavia. I would say she is exotic and minimal at the same time. She dresses fashionably casual, almost masculine like, but she is very sexy. She has beautiful peachy pale skin, dark hair and big deep brown eyes. As for character and personality she is strong and determined, has a good sense for business and humor, but rules with a soft heart.
Now if you wanna narrow the options down a bit, since there is an infinity out there...One can be more precise  choosing for example the occasion when the fragrance will be utilized . Like categorizing after different time slots:
*"Daytime" such as work or study, her you can consider what kind of job she has and what can be suitable/appropriate etc.                                               *"Afternoon" activity, maybe a hobby or leisure, what does she like and what would be in tune with that.                                                                          *"Evening" for coktail party, dinner invitations/romantic encounters.
I am going to choose a perfume that would be suitable for daytime at work for Salomeh. I will write down my spontaneous choice. 
I would look for a woody floral perfume. One that is somewhat green and spicy. My motifs here are:
A somewhat pronounced woody base notes makes a statement, the flower is feminine  ( feminine and masculine are merely archetypes and can be applied to any sex), green notes makes you alert the spices gives it that extra pinch. 
Needs to be woody & floral without being too invasive but catches your attention. a subtle but decisive statement keeping you alert and enticed. The freshness of the green and spicy notes makes it pleasurable to be around. To me these kind of fragrances are modern and bold, but due to the presence of "the flower" it stays true to heritage.