Etiquette is the grammar of the language of civilized behavior.

Etiquette. Birth - engagement - marriage - mourning - contact at the table - correspondence.

Left: Do not introduce a lady to a man. And why does the young man remain seated? Both young men are wrong: this can clearly be read from the face of the lady.
Right: This is correct: the young man is introduced; the lady remains seated and reaches for his hand.

A common mistake: the young man has failed to introduce the acquaintance who addresses him to his female companion. (I like her shoes!)

This is the proper way: immidiately introduce unaquainted people to each other. (Note that he only takes off his hat to her and she keeps her glove on.)

Left: Do not let your female acquaintance wait until you have wormed off your glove.
Right: Rather extend your gloved hand and say: "excuse my glove please." (Interesting that at this point he is still wearing his hat. During the initial greeting he could have taken it off. Besides, while talking to her he is not supposed to wear his hat anyway.)

Problems at a reception. Left: The improper way; do not unelegantly grasp your glass and do not take salties with your gloved hand. Right: This is better; the glove has been taken off in time and the cigarette has been put aside for a little while.

Left: A tender goodbye in front of the office door is inconvenient and slightly ridiculous.
Middle: It is romantic but not correct to walk the streets in close embrace.
Right: Naughty! It is very impolite of the young man to remain seated on his bike.

A well mannered gentleman rises when a lady comes over to his table for a chat; his female companion may remain seated.