Thy Name Be
One thing I find annoying about some fantasy type novels is the choices of names for people, places and things. I understand that it is not an easy task to come up with new words that haven't been used thousands of times before, and trying to avoid rehashing the same creature names makes it harder still, but I have to be able to decipher the pronunciation quickly or that word will annoy me for the rest of the book. If that word is the name of a main character, things could get ugly. As a rule, I also think it is wise to avoid chaining consonants together.
One author who is guilty of this annoyance is Cecilia Dart Thornton. Perfect example is Gwragedd Annwn. The problem with these types of words is I attempt to sound them out so my reading-voice is pronouncing things correctly. If I stumble every time I come to a word, I'm not going to have a good time with the story because the impact and meaning of the words is lost.
When a character appears, like 'Fitz the dog-boy', the association with the name is instant and the story can continue. When a name like Gwragedd comes along, my brain goes 'Oh it's hablemego.' or something to that effect, and I stare at the word more to crack the code. Perhaps if I was more literate or studied in English dialects, I would not glance twice, but I'm not and I like to be guided.
Tolkien, of course, is the master of the made up name. Most of them are word caramel; Lothlorien, Rohirrim, Pelennor. The best thing about all of these words is he tells you how to say them in the appendices. I don't expect every book to come with 150 pages of extra story, but a helping hand would be nice.