Well, I grew roses and lavender, so they were always available. One year I dried and grated lemon and orange rinds. It often depended upon what was available at the local "hippy shop." Cinnamon, basil, nutmeg, ginger--these were always favorites. Oh! dried apple too--though this one got a little funky if the apples weren't dried enough.

My favorite combo was always lavender and lemon peel.

Hops for restful slumber.
Mugwort for magical dreaming.
A pinch of orris root to preserve the scents.
Flax seed because it feels really cool in a pillow!