Teddy smelled chocolate, the Potters' home, and strawberry perfume when his class brewed Amorentia.
Teddy is very fond of chocolate and it is one of the things that brings him a lot of comfort. It helps him to feel connected to his Dad as well.
The Potters' home, where Teddy spent most of his time growing up, has a very distinct smell. The best way to describe it is a mix of Pine and Ginny's perfume, which is a dark, sweet smell.
The strawberry perfume that Teddy smelled is an uncommon one. There is only one person he knows that wears "Fraises et Pluie D'été". It's a french perfume that Victoire Weasley always picks up when she is visiting the other side of her family.