Snap! We have lemon trees blossoming here in Oz at the moment too and I've been meaning to get out there and pick a few flowers to tincture. I went for an early morning meander around my locale and was greeted with not long lemon blossom, but heritage roses ~ divine!
Roses, now that would be marvelous. All my roses are scented, but this year for some reason, they're weak. Try tincturing or evulsing some of those lemon blossoms -- you won't be disappointed :)
I have one bloom on my pink lemon tree that i planted last year and that one bloom smell so so good.
It doesn't take many blossoms to smell up a space -- these that I had made the house smell like an orange grove! All the citrus, with the exception of grapefruit, are blooming right now, so a drive through the country is magical with the scent of white flowers.