הרחת בשמים ביו"כ

On יו"כ afternoon many have the custom (which I have, incidentally, never specifically come across in the minhagic literature, but rather 'only' observed being done myself [1]) to take advantage of the break between services and smell an אתרוג or the like (often one that is spiced with cloves). The purpose of doing so is twofold: 1) to revive one's senses after a tiring day and 2) on יו"כ we do not have festive meals; to that end, we may be missing some of the 100 ברכות that one is supposed to make on a daily basis [2].

One should only keep in mind that the proper ברכה on an אתרוג is ברוך...הנותן ריח טוב בפירות [3], not the generic בורא מיני בשמים that one makes for הבדלה.

[1] By this point in halachic history, nearly any מנהג that exists will written about somewhere (especially a straightforward one, as opposed to an esoteric one). There are still some, however, that are yet the domain of תורה שבעל פה (as all מנהגים ideally should be - by definition there are no מנהגים codified in תנך). Another example that comes to mind is decorating the shul in white for the High Holidays (a subject for an article in its own right), which merits nary a mention anywhere in our entire halachic corpus.

[2] as per :מנחות מג and שו"ע או"ח מו:ג

[3] שם או"ח קטז:ב