I’ve already done much of this, but I’ll post it in order to stay on course.
Exercise: Listen to how different syllables sound to you. Do they excite you? Do you associate a particular sound with an emotion or place or memory? Write down some generic preferences for your languages– “I want the language spoken by the elves to sound like water, and the language spoken by the dwarves to sound like gravel rubbing together” and then go listen to what those things sound like. Write down the syllables you hear when you run a faucet or sit by a stream, for instance. Those sounds will be your “root” syllables when making up your names for places and people and things.
Bonus Exercise: If you want language to play a strong role in setting the mood of your story, visit the naming exercises from the page mentioned above, and sort out some of your names for your people, places, and things. Note that, in doing this, you will likely get a firmer grip on your character’s background, as well as need to pull out your map to now fill in the names of some of your key landmarks and settlements. This will probably take an addition 15-30 minutes more.
When I started Flame, one of the first things I did was to grab Holly Lisle’s Language Clinic†, and the second thing was to follow the directions. I found out some fascinating things–like that my elves put great import on someone’s age, so pretty much no human ever could reason with their Elders. I learned that Vralajii is an intricate language with a lot of rules, and Flame uses it pretty much never if she can manage it. I even worked up some letter usage and my friend made me a wordgen.
There were other languages, of course, but I spent a lot of time on Vralajii so I only worked up a few rules and sounds for the others. Lory’s spellcasting needed to sound completely different from Tolor’s holy language, for instance. (And how exactly is it it that I’m only now noticing the similar names? Need to fix that…)
I need to–and will–put more time in on the dwarven language before I get back to them. I need to figure out some language groups, since the population has spread in odd ways. But I’m calling this one done for now, because I’ve already done tons of work on it. (Especially since none of the places are going to be named in any of the languages I already created.)
†So, so worth the money! My wholehearted endorsement. Not only did I create a bunch of words and the rules to create an entire language if needed, I learned a lot about my story. If you’re at all tempted, get it. For reals.