Darken up the hotspots where the flash hits the face (tip of the nose, between the eyebrows, cheekbones, chin, lower neck, forehead) and lighten up the natural shadows (below hairline, around mouth specially below nose, around eyes, sides of nose, just below chin).
Remove stray hair(s). Smooth skin as to nearly remove any natural "texture" (aka enhancing makeup). Whiten teeth, cover up scars, bring out the color in the eyes, whiten eyes, don't use a distracting background (like don't photograph her infront of a burning building because no one will care about her, they'll be looking at the fire), have her wear colors that she looks great in (complimenting colors/patterns), do profile shots, close ups/full lengths/secenic photos to see which is best, use props that compliment her (roses, puppies/kittens, children, horses...while some would look great holding a rose, they might be uncomfortable near an animal wich would cause them not to smile naturally, or they might be allergic to flowers so use pets/small children instead-->infants are always a big hit), different poses but nothing to ecentric, don't wear anything flashy or revealing as it'll take away from the subject(her).
If you can get digital, then do like projectfocus
said and try some subtle filters, again, don't overdo it as you don't want to take away from her.
Other than those baiscs (which some I missed no doubt) it's just hit and miss as far as exactly what you're looking to do......or was all this to much information? LOL!
Hope it helps