Simply top-notch smelling strips, Mouillettes, scent strips or perfume test strips as they are sometimes called. The specially absorbent board used to make these is used by some of the most expensive perfume brands in the world.
While these are perfect for evaluating raw materials, newly made blends and so on, they can also be used to test a finished perfume in an atomiser: in that case hold the narrow end and spray onto the unprinted side of the wide end.
Whatever you’re evaluating, hold the part of the strip containing the sample near to your nose without touching it and sniff gently. For exceptionally delicate materials you may find it helps to have your mouth slightly open so as to get the inhale some of the scent through your mouth, addressing a different area of the olfactory bulb – the part of your nose that detects everything you can smell.