I'll email the finished piece as a jpeg in a high resolution (at least 300 dpi). Or a Tiff file or whatever format you want.
Work that is commercial in nature, you should email and message me directly about. If it is related to published RPG artwork, I'm ok with negotiating down for the sake of the hobby. I'm more than aware that RPG industry stuff tends to slip between shoestring and bubblegum for budgeting.