Writers seek every secret advantage that they can to make characters appealing. Choosing a good name for the character is supposed to confer one of those advantages. The only rules I see for naming a fictional person is to make it match the person and make it pronounceable. I’ll deal with the second rule, first.
Readers may not be comfortable discussing your book, if they are unsure how to pronounce the characters’ names. I used the slightly obscure Swedish name, Tove, for a female character and found initial readers were embarrassed because they didn’t know if it rhymed with dove or clove. Actually, it didn’t rhyme with either. Tove is pronounced To-vay, which may have sounded beautiful rolling off my tongue, but eventually I gave in and changed it.
Typically, I use uncommon, but not bizarre names for my major characters based on the time period of their life. As most of my writing is set in the late 20th and early 21st century they may receive one that is a little old-fashioned. However, people assume information based on their own background no matter when a story is set. In a series of short stories occurring in the late 1990’s one main character is a male child named Walt who owns a Gameboy. Some people thought he was living in the 1950’s or was an older man just because of the out-of-date name. They ignored what they knew about gaming systems or events in the late 1990’s. My take away from this experience is that the right name may depend on the experience of the reader.
The question continues to arise about naming characters in science fiction and fantasy. I often hear the old adage applied to that genre–invent a name that matches the character. That often means creating a name based on Germanic languages. Darth Vadar means dark father and Mordor sound like murder. However, the world is full of other languages from which we can borrow sounds for unique, but still pronounceable, names. Basque and Banjar are two of my favorites.
The only research I have come across on the sound of names found across cultures is the bouba/kiki effect. Wolfgang Köhler (a German speaker) tried to determine which speech sounds were matched to specific shapes across areas speaking various languages throughout the world. The “kiki” sound is associated with sharp pointed shapes, but often used in female names like Kitty. The “bouba” sound matches bulgier and rounder shapes, and the sound is often attached to male names like Bubba.
A shortcut for choosing names for fictional characters from another world is to select names that are similar to common names, and then switch out a pair of letters. However, no matter what name you create for a science fiction or fantasy character, it will probably be a real word or name in some language. So, Google the invented name (just like you do for your own) to find out what it really means and avoid later embarrassment.
As you are writing your fantasy/science fiction novel, choose common names as placeholders for efficiency’s sake, and to take the load off the spell checker. When you determine the real name that matches your character, use the search and replace function. However, avoid names with diacritics (accent, cedillas, etc.) because this can create more nightmares preparing your manuscript than you can imagine.
So what is the secret to naming characters? There actually is none. As long as the name is not outrageous we will remember Anna Karenina, Fitzwilliam Darcy, and Atticus Finch not because their names appeal to us, but because the characters are compelling.