I never understood that whole over-sized glass swilling flared nostril business.
The idea of tasting a carefully produced drink and then just spitting it out seems wasteful to me.
Personally I find it best to enjoy a cider's bouquet immediately before and after swallowing.
Obviously a strong apple aroma is a given, but you may also be able to distinguish
more subtle qualities of the fruit and even the fermentation and storage environments.
Resinous, woody notes are often sought, typically by aging in wooden (normally oak) barrels,
but also by using specific apple varieties, such as Woodbine.
Grassy, straw-like qualities are also highly-prized,
which I tend to associate with ciders from Wiltshire and Hampshire.
Traditional straw-pressed methods give the best examples,
but these tend to be rare nowadays.
Other more subtle aromas can include hints of:
strawberry, banana, nuts, butter, orange, honey among others.