The Second Accord

Nobody was quite sure what to call the celebration, but that one should be held was a matter of galactic consensus. Referring to "peace" seemed inappropriate since there had never been a war; indeed, the determination of every analyst and computation on both sides that there never would be was what prompted the present relief. Till the moment itself, none could be honest in claiming he knew whether an encounter between intelligent species would result in the extermination of one as many predicted against the theories of approximately as many.
The formal ceremony to confirm eternal non-agression took place in a space installation constructed for that occasion, a trifling endeavor for a pair of interstellar civilizations. Numerous heads of state attended (the investigations following first contact provided another point of reassurance in that neither species had united into a single nation, a cause of anxiety). Lesser politicians considered themselves either lucky to be invited or else took it as a portent of a continued rise, but as for the deal-makers whom few of the public knew for all that everyone there did, they regarded their inclusion as nothing exceptional. A smattering of celebrities enlivened the event, less from their charm and more from the attempts of either species to explain the sources of their fame.
That procedure as well as much additional conversation impinged on the main disappointment of the historic encounter. Just as the two species had no cause for conflict, neither did they have any for less-violent intercourse.
"This music, I am sorry to say, is discordant to my human ears."
"Your 'pineapple' is not displeasing in shape, but it is quite inedible for us."
"Humor barely survives differences in language. I am unsurprised that none of yours makes it across."
"I have no reason to denigrate your archery, nor any to prefer it over our own."
"I expect you have no culinary use for this garlic. It is only a shame you have no vampires!"
Amid laughs, the other party requested an explanation, out of politeness merely until he heard it.
"Those exist among you?"
"They do. It was once thought they were fiction, but the fact has become unpleasantly evident. There is some speculation that colonization of the moon has led to an increase in their power and numbers."
"How curious that we have a similar monster! It can transfix a man with its horrible eye before feeding." "That is, it can transfix a man of your species. Is that not so? Likewise for ours, I believe."
"An experiment does suggest itself."
Vampires and other unsavory creatures had cause to lament the swift creation of the monster hunter exchange program.
Finis

The Three Kinds of Interplanetary Science Fiction

1) Everybody listens to the same bands
2) Every planet has its own bands
3) Every region on the planet has its own bands

Obviously there's going to be some galactic superstars and some local specialties, but in a normal week, seven of the top ten songs the average person hears are shared X far.

I Used to Know This

What do you call that kind of magic that gets stronger the more autographs you have in your signature book? I can't believe I forgot.

Worldbuilding Tips

The first thing everybody wants to know about a futuristic milieu is what kind of ads they have. Celebrity endorsements? Regular people like you and me? A guy in a lab coat explaining the scientific properties that make one product the best? Don't try to tell us there aren't ads. Don't try it.