Appropriate means 'fitting for the occasion'.
His behavior was appropriate for the occasion
Jeans are inappropriate for the occasion, wear this appropriate dress.
To be modest means also to be appropriate for occasion and time.
You should wear clothes appropriate for the occasion.
An appropriate occasion to give a heart locket necklace as a gift would be any kind of occasion. Wedding Anniversary, Mother's Day, Valentine's Day, and Christmas are a few occasions one could give a heart locket necklace as a gift.
We should wear clothing that is appropriate to the weather, or the occasion.
When you want to express a complicated idea
It was necessary for Margaret to subdue her enthusiasm, as this was a solemn occasion.
"Ohayou gozaimasu" is a polite morning greeting appropriate for any occasion, particularly if you do not know someone's name. It is not necessary to insert any kind of "sir" into it; the respectfulness is inherent in the politeness of the phrase.
Sending flowers is appropriate for almost any occasion; however, the most appropriate ones would be Valentine's day, birthdays, and anniversaries because they can involve romance in some way.
Diane Sawyer wears stockings on the appropriate occasion; as does everyone else that has sense.