If you have hard water, your stream vents in your iron can also get clogged. When you are ironing clothes and start to notice spots that were not there before, try this remedy.
Pour equal amounts of distilled water and vinegar into your irons reservoir. Turn the iron on and make it stream and spray until the reservoir is empty. Your iron will be good as new.
If your iron is particularly clogged you may need to use straight vinegar. Remember to flush it with water when you are done.