Katelle came about because of "Kate" or "Katie," the latter of which I went by for a while until she became known ICly as simply "Kate." The "-elle" is a remnant of both French class in highschool (which I was taking at the time of rolling this character) and another character I had on a different server, Sophielle.
Ketani (my warlock),who came long before Katelle, was named for a character I wrote for a story group comprised of several friends in high school. She was an assassin type, regrettably a tad on the OP side with her use of psionics (it was a long time ago ><). The name was ORIGINALLY that of an OC I wrote during my fanfiction phase, and loosely based off of another OC from a fanfiction I was reading at the time (and still am because the author takes forever to update and it's just really friggin' amazing all the way around).
Another "K" name (I apparently really like that letter) is Kriabryve - my little Goblin hunterbabby. For that one, I used a strategy I often do when making a new character: I spammed the Fel out of the "Randomize" button and took segments of various names I found, stringing them together with some extra letters thrown in between to make it sound better. Also, "Kria" just sounds really cute.
Omigod, a name that doesn't start with a "K" - Buckles! Originally intended to be a bank alt, I gave her an RP name (Regina Doltrim) and a backstory which made her character name make sense. The daughter of a blacksmith, she learned her father's trade and practiced on making buckles more than anything else. The nickname is a relic of her childhood.
Other characters I've had over the years, comprised of toons that I rarely play or names that I go back to when creating a new character, include Tamarynn, Azshaloria, Trinzie (always a female gnome), Sophielle, Dahliana, Sabine, and Sarise. These have either come from the same method as Kriabryve's (spamming "Randomize") or have bits and pieces from other various and sometimes unknown influences.
EDIT: I'm apparently very, very wordy today. ._. MY BAD.