My dog's dry skin

Greetings to all:
     My dog Molly is about 4 years old (former pound puppy), 14 lbs,
chihuahua/beagle mix.  I know I'm not supposed to bathe her "too" often, and
I use gentle dog shampoos - but, she still has flaky skin.  She eats a
brand-name dog chow, drinks plenty of fresh water, and is otherwise fit and
healthy.
     Does anyone out there know of a good "home remedy" I could put on her
coat - something safe and inexpensive - to help moisturize her skin, and not
give her diarrhea or otherwise make her feel sick?
     Thanks for any help - Freckledgrrl