Real life names, not so much. Although I might subconsciously do it, I run into so many names during work.
I often use fiction as a reference. Specifically for Sims Medieval, I've had a Harry Potter themed kingdom, a Ranger's Apprentice themed kingdom, plans for a Riyria themed kingdom, etc.
For sims 4, I either browse behindthename, or use the randomizer.
I do occasionally write down names I want to use, regardless of where I heard them. But I have separate lists for first names and surnames so my sims end up having a different combination.