Years ago, my brother gave me one of the greatest lessons as a chef; encouraging me to constantly practice deciphering and then describing (to myself) what flavors I tasted in any given dish. Not just the taste but the entire sensory experience a spice inspired. From then on I subconsciously archived flavors that I tasted from the most simple to complex. That process may be the best exercise to learn the use of spice.
Using spice is a bit like alchemy. Success demands balancing flavor combinations that can differ based upon temperature, cooking style, etc. Magical when it works, but challenging to make the magic. The alchemy is propelled when the magician (okay, cook, baker, food prep guy or gal!) can find guidance from past sensory experience.
About a year ago I met someone who approaches magician status, Lior Lev Secarz , the Israeli-born spice master who runs La Boite a Epice in New York's "Hell's Kitchen". Visiting his gallery is a sensory series of explosions – less singular than layers. His use of spice extends to baked goods, that can be sampled in his boxes of biscuits laden with flavorful ganaches and fruit and, of course, spice.
Recently, I used some of Lior's spices with with hot crossed buns (Yemen #10) and for a roast dorade (Cancale #11). Their exotic names are wonderful, but what most enchants is their potential impact on your kitchen, providing a way to turn moments cooking or baking into a journey of flavor.