When it comes to fragrance, for me the only month that rivals May is December, when the smells of the Christmas Holidays pervade. But while Christmas represents a broad range of smells that I associate almost exclusively with the Holidays (or at least in Holiday-like combinations), May is most of all about the flowers.
Unfortunately, there are no guarantees that blending any two or three random flowers together will bring about the desired result. But it might, so don't be afraid to experiment. For the less adventurous, however, here are some of my favorite floral combinations and blends:
Lavender, Jasmine and Lilac, in any combination, either as duos or all three
Cherry Blossom and Baby Powder
Apple Blossom and Iris
Lily of the Valley and Lotus Flower
Peony and Honeysuckle
Red Poppies and Rain
And any of these can be brightened with a fresh, green scent, like Firefly or New Leaf - or a darker green, like Ivy, works equally well. I just personally prefer my greens lighter and brighter this time of year.