Make a solution with one teaspoon clear dishwashing detergent to one cup of warm water. Put that in a spray bottle and spray on the spot. Blot out with a white hand towel (actually fold the towel and...
Tea is a type of stain known as a tannin. They are some of the easiest stains to clean. Just throw the stained clothing into a washer with some detergent, and wash it with hot water.
you can put the tea mugs in a light solution of water and bleach. Don't leave them in too long. then wash them. If you want to be more green about it use salt and lemon juice and scrub the stains...
Wash the plastic with dishwasher cleanser. If you have a gel, apply it directly. If you have a powder, make a paste and apply. A light stain may come off instantly, or require a few minutes of soak...