I have an animal around the house that likes to run about and play, and his claws are not always kind to my wood floors. You can have the perfect wood floor, but that one little spot or dent not only ruins the floor, but can drag down the entire living area. But regardless of the damage, you can restore your wood floor to that classic, pristine shine you once loved when you first bought the house. In my case, I dealt with superficial marks from my dog's claws by doing the following.
Try the Basics
Most of the time, wood floor scratches are minor and can be wiped away with a simple cloth and mineral spirits. Stain markers are also a cheap and viable way to get rid of stains, but be sure that the stain utensil matches the mark you're trying to get rid of. When the marker is applied, rub the color in with a soft cloth. You can also paint the floor with the same coloring as the rest of your floor, and having an extra can now and then will aid you in future scratches.
You can buffer away minor scratches with sandpaper grits or steel wool.
Sand along the line of the wood grain, and only buff around the area of the scratch. For polyurethane floors, you can use sanding screen or a scouring pad.
For deeper scratches, paste wax will fill in any damaged marks. If you're dealing with any dents from moved furniture, pour water over the surface of the damaged area, and apply heat from an iron or heat gun. This will swell the wood back to its original shape. Make sure you are using mild heat.
And this leads to my next point about water stains. If you are dealing with any unruly water markings, fold a cloth in half and place it over the stain. Take that same iron, and apply medium heat over the cloth, going back and forth. Hopefully, the heat will lift away any ingrained stains in the flooring.
Water stains are especially found in areas where plant watering is common. If you have any over-hanging plants, place a small rug or some other form of covering under the plant to avoid extensive floor damage.
Now here comes the tricky part...
If you are dealing with a stain in the floor, you may have to sand the area, or use bleach, followed by refinishing the area with the same color. You'll want to use bleach for darker stains or oxalic acid, and then follow with 150-grit sanding. This is a process that is best left to professionals, but if you are up to the task, here is what to do.
Apply a sander with 100 grit sand paper and follow with 150 grit. Once finished, vacuum the area and follow with water for any latex-based stains, or mineral spirits for anything oil-based.
For the next part, you'll have to mix up a good concoction that comes closest to matching the wood floor. You may want to dabble your mixture on a sample piece of wood before applying. If at all possible, take a sample of your wood flooring and bring it to a local hardware store where an associate can help you find the best possible match.
And for pieces that need new flooring altogether, measure and cut a piece of new wood flooring, and either glue or nail it to the sub-floor. Construction adhesive works fine as well. As in the case of stains, you may want to contact a wood-floor specialist or a local handy man.