She's never voiced her but I always read Artemis in YJ Cheshire voice. Has kind of the overwhelming arrogance I associate with Artemis.
Reading Vordan's blog on Superman's main "sin" being wrath/anger had me kind of think what Wonder Woman's equivalent and I figured having something of an ego (even if justified) sounds like it would Diana and a lot other Wonder characters.
In terms of how she's characterized? I liked how Phil Jimenez said it when he described his creative process for WW, regal but not haughty.