I use several techniques.
1. There are some names I like that I reuse.
2. For ethnic sims I google names that fit.
3. I have used the game random name generator similar to how others use it.
4. Sometimes I use a theme. When I first started playing Late Night I created 4 males with archangel names - Michael, Gabriel, Raphael and Uriel. I still use the first 3 although I sometimes use Rafe instead of Raphael. I also created 4 fallen angels who where vampires. The only ones I remember were Azael and Lucien (loosely based on Lucifer). I still often name a vampire with long blond hair as Lucien.