There are lots of flowers with pretty scents, some of which you can only smell in the evenings, and some of which, as the bears have just discovered, don't even have flowers, just leaves, but they smell lovely too!
Perhaps you could take a trip round your garden, or out in the countryside, and try smelling all the plants you come across. You could even list them in the order of the scents you liked the best! The bears tried to do that, but ended up arguing about whether roses or sweet peas smelled the nicest, though Tommy still insisted that clover was the best!! Be careful though and check for bees before you put your nose anywhere near a flower - they seem to love the smell of them too!!