Hints and tips
Perfumes are a very idiosyncratic thing, as anyone will know who's ever had a perfume bought for them that simply doesn't work - or even when you've bought something for yourself that later doesn't work (the 'what was I thinking?' issue). Here are some common problems and tips on making your existing perfumes work for you.
It's too strong
Use less of it. Well, doh. But the average spray delivers quite a blast and when your perfume's made of strong ingredients, it might all be a bit too much. The old trick of spraying the fume into the air and then walking through it does work, but it gets it all over the outside of you - your clothes and hair - and this may not be the best option, especially if you're just about to get on the Tube. One trick used by perfumistas is to spray perfume on a cotton-wool pad and tuck the pad into your bra, where your body heat will warm it and create private wafts of fragrance that only those close to you will pick up. You can also use the cotton pad to just apply the fume to your wrists, cleavage and backs of your knees: with a very strong perfume like Giorgio of Beverly Hills, a Q-tip is enough. You can also use strong perfumes to revitalise your car air freshener, in your vacuum cleaner filter, on a cotton-wool pad at the bottom of a wastebin or in your trainers or sportsbag, or sprayed into bicarb of soda and sprinkled as a carpet freshener.
It's too weak
No matter how much of it you put on, you can't smell it 30 minutes later. To start with, you're probably using either a cologne or eau de toilette, which is a weak formulation, so if you like the fragrance, look for an eau de parfum or parfum extrait. If that's not do-able, you can slow down the escape of the volatile molecules in perfume by rubbing some Vaseline on your wrists or wearing a heavy body cream, and spraying the perfume onto that. Perfume is also slower to evaporate if you spray it on your clothes rather than yourself. With notoriously volatile lemon and citrus fragrances, however, you may have to accept that they lack longevity - this can really be quite useful if you just want to spruce up before going out to dinner, as you won't interfere with the food. Consider also using weak perfumes in the bath (just spritz the water 10-12 times before you get in), or sprayed on your towels just before wrapping yourself in them, or as a pillow spray. Better still, look for the same fragrance in a body lotion, soap or bath product - some scents just work better as toiletries rather than perfumes and are none the worse for that.
You like the top notes but not the base notes
Spray it on your pillow before sleep - that way you get the best half hour and are asleep before the rest of it kicks in.
You like the base notes but not the top notes
This one is trickier, as you do have to live through the worst of it before you get to the best of it - something that afflicts me with First by Van Cleef et Arpels. Keep the perfume on your wrists only and don't put your hands near your face for an hour or two, or spray it on a scarf and don't wear it until the fume sweetens.
It's too flowery or too spicy
Try using it to scent drawer liners and cotton-wool balls placed among clothes in storage. Both florals and orientals last well on paper and any perfume at all will work as a moth repellent, including citrus. When scenting drawer liners, spray abundantly and then leave the paper to dry for 10 minutes or so. With cotton-wool balls, soak the cotton-wool, then place it in a cloth bag (those little organza bags that so much jewellery comes in are useful for this), so that the scent doesn't stain your clothing. This technique has worked well for me to use up some cheap musks I bought at a discount store in a moment of madness.
It smells like room freshener
Use it as one. There's no obligation to use perfume on yourself. I use Yardley's Lavender EDT this way - way too harsh a perfume to actually use on the body, but it's nice enough in the loo. The same applies, sadly, to Serge Lutens' Gris Clair.
It's just not right for you
A perfume has to hit you at the right stage of your life - often, as women get older, they find they can wear fragrances that were just too grown-up and glamourous when they were younger. If you really like a fragrance but it's 'not you', either give it away to someone who'll appreciate it (the best solution if it's too girly), or close it tight, rebox it and put it somewhere cool. Take it out once a year and try it, and if it's still not you after three years, it's time to pass it on. IMHO, a perfume has to be worn several times before you get a grip on its true character, so don't throw out what may one day be your true love until you've given him enough time to reveal himself.