I don't give it too much thought, but will pick a name that sounds "right" to me. I tend to choose names that are common enough that I've actually known people with them. I know some authors that like to go with really obscure names, but that doesn't work for me. I lean towards names like Lisa, Matt, Tammy, Jim, Ravi, etc.
I also mostly try to avoid reusing names. At some point I may need to write out a list of all the names I've used, to avoid duplicates, but haven't bothered yet.