Do you grow the deliciously scented annual Matthiola longipetala - night scented stock?
A tiny sprig or two will scent the room in late evening into early morning. I have a little jar of it on most windowsills throughout the house.
It doesn't look much in the garden as the flowers close in daytime, and it is often grown along with Malcomia maritima, the pretty Virginian stock, to give colour during the day.
They are both easy to grow and there is probably still time to sow a row of them for late summer/autumn flowers.
It was one of my husband Barry's favourites and I am picking from the sowing I made when he died in February, so there is an added poignancy to the exquisite perfume.
Here is an article on the night garden by one of my favourite garden writers Dan Pearson.