Before you can make this natural room fragrance you have to collect together all manner of plant materials to bulk out the pot pourri and to scent it. Some of the items that are useful are:
Clove pinks petals (also known as the Gillyflower)
Scented Geranium petals
Lavender Leaves and flowers
Lemon balm leaves
Mint leaves - there are various varieties available such as apple, orange, chocolate, eau de cologne, spearmint
Sweet pea flowers
Bergamot leaves and flowers
Whole dried flower heads such as dahlia peony rose pinks or rosebuds
To name but a few
Also orange lemon and lime peels dried
So now we have things growing in the garden, once the flowers blossom or we have a splurge of new growth with leaves it is worth collecting and then drying the material collected very carefully for use later on.
Store all items separately to start with because some of the flowers and leaves can be used for teas and tisanes as well as for pot pourri. Go on start collecting now and then we can start doing some mixing and blending as the season progresses.