All is not lost if you forgot to use a drink coaster and got a water mark or water ring on your wood furniture (or even worse, someone else's wood furniture).
Here are several options for removing the water mark and making your furniture as good as new.
Make sure to test all methods in an inconspicuous area on your wood furniture to ensure it does not damage your furniture.
Remove Standing Water
Always remove any standing water on wood furniture before trying to remove the water mark.
Try to wipe up the water as soon as possible to minimize the wood discoloration.
Start removing the water using a soft cloth.
Once most of the water is removed, you can use a soft paper towel or tissue to try and remove more.
Try to get the wood as dry as possible.
Sometimes furniture seems to have a water mark, however the sheen may be disturbed by something that was placed on the piece of furniture.
Before attempting any other water mark removal technique, try using furniture polish to see if you can remove the discoloration and bring your wood furniture back to life.
If the furniture polish does not work, follow one of the methods below.
Using a soft cloth, try rubbing toothpaste (not gel) into the water ring.
Let the toothpaste sit on the water mark for around 15 minutes then wipe off.
Repeat if necessary.
Try using the heat from a clothing iron to remove the water ring.
Put a clean cloth on the discolored wood and cover it with a warm (not hot) iron without steam.
Leave the iron on the cloth for a few seconds and check the progress of your water mark removal.
Olive Oil or Mayonnaise
Try rubbing olive oil or Mayonnaise on a water mark to make it go away.
Let the oil or mayonnaise sit for about 15 minutes before wiping off. Repeat as required.
Furniture Restorer in a Can
You can use a furniture restoring product found in most home improvement stores to help remove water spots.
Follow the directions on your particular product to get the best results.
Professional Furniture Refinisher
If all else fails, hire a professional furniture refinisher to fix your furniture.
The furniture refinisher may have to strip and restain your entire piece of furniture to remove the water stain.
Be prepared to pay several hundred dollars for this service.