For characters of a similar background to me, I just make them up based on what seems to suit them. Sometimes I change them later. NEVER name a character "Will," it's a nightmare to find/replace.

For characters of a different ethnicity/nationality, I look up the top 100 most common names and surnames that match their background for their birth year and then mix and match until I get one that when I google it, there are multiple LinkedIn profiles for that name. That way I feel pretty confident it's a believable name for that person to have.

I also try not to give characters names that begin with the same letter as another character. I think it makes it easier for readers.