I'm not very creative to be honest. My royals and nobles get names that start with "von" (German for "from/of") and then something I can think of. German is great in just adding nouns together. One family is called "von Beerenhausen" which means "from town/village of berries". Other names are just syllables I played with. Especially my farmer family Tiuwana.
First names are also kind of spontanious. Often taken from tv series or books. My in game second born generation of nobles mostly get second names. Like Amalia + name of grandmother von Xyz. Some merchant & military family do this too. With time I want to recycle names to kind of connect the past and future with each other.

I too have used other languages for family surnames. The Brueder family originally consisted of three brothers (and their sister), "Brueder" simply being German for "brother". The unsavoury Voleuse family is named after the feminine form of the French "voleur", meaning "thief", though several generations later I can gladly say that they are upstandingly respectable pillars of the community.

Then there's the Sonomme family, which is also French but a pun, in that it sounds like either "sans nom" (without a name or nameless) or "sans homme" (without a man). The original Sonomme was Mimi, a spirited free-wheeler who wasn't going to get tied down with anyone. Her two kids had different fathers, neither of whom she settled down with, and now there are several Sonomme households dotted about the 'hood. Though some of them have rather let the family name down by getting hitched.