For me, I roleplay so each of my characters usually has a story. I don't gear them all, but I do like to level them. I have one character, a mage, who goes by two different names in his stories, and some others who are dual-classed, like the fire mage turned warlock, and the rogue turned mage. Sometimes I like to roll different races too.
Rogues, warriors and hunters tend to be my first pick for 'regular' people. I have a blood elf who loves the outdoors, but owns a furniture shop in Silvermoon. He's a hunter, but in-character, he's just a shop owner.
I also have max level characters on high pop and low pop realms so I can cross realm invite myself for celestial/Ordos on the high pop ones and camp tlpd spawn points on the low pop ones.