Nicklichkeiten bedeuted ein paar Schrullen, Besonderheiten, Spleens, eben Fehler aber sehr sehr sanft ausgedrückt

I think this is the idiomatic equivalent in English. Even if it looks like French! :-)

particularly where a British person is concerned. Assuming Kathi's explanation of the term - never heard of it!

Nichtigkeiten exists in Germany, like someone said before, it would be somehting along the lines of "small nothings"

But when you are referring to presents given to someone, just small things, it could also be
Niedlichkeiten - small sweet little gifts that don't cost much and usually aren't well-chosen...

In any case, it's small gifts - the difference between the German words being in the amount of "sweetness/cuteness" in the presents :-).

HTH
Sibyl

"Nicklichkeit" in my opinion is "nastiness", although that may be too strong, so my suggestion is "minor nastiness". Like a "mild" version of foul-play in sport.

HTH