The length and depth of the scratch is the main factor in deciding whether your heels are salvageable. Shallow surface scratches that remove the surface color but don't dig too far into the shoe are almost always repairable. Deeper scratches and gouges that extend past the surface into the inner material may be fixable, depending on what the shoe is made of. Rub the scratch gently with your finger and see if the scratch changes color or gets lighter. If so, the shoe isn't destined for the garbage.
Shoes made from such fabrics as silk, satin and canvas are some of the most difficult to repair. Scratches in fabric shoes sever the weave in the material, transforming a minor tear into a shoe-wide fashion disaster. No-sew fabric glue is your best defense in the war on scratches. Add a drop of glue to the center of the scratch and spread it with your fingers. Let the glue dry and buff the scratch down with super-fine sandpaper to smooth out the shoe's surface.
Leather shoes are simpler to repair than fabric shoes, but all scratches should be fixed as soon as possible to preserve the integrity of the heel. Dampen the corner of a rag with leather oil and buff the oil over each scratch. Rub the surface firmly to push the oil into the deepest part of the blemish. Let the oil soak in for an hour, then wipe away any excess on the surface. Dip a cotton swab in a tub of shoe polish the same color as the shoe and fill in the scratch to disguise the blemish.
An Ounce of Prevention
Preventing scratches is simpler than repairing them. Walk with your feet slightly apart to prevent contact scratches, and use caution when entering and exiting vehicles and climbing stairs. Avoid wearing heels while walking over such damaging surfaces as gravel, sand or salted sidewalks. Wear a pair of sturdy boots or tennis shoes, and swap into your heels once you arrive at your destination.