How to Make a Paper Cup from a Sheet of Printer Paper

Take a single sheet of printer paper and lay it flat on the table. Use a clean piece of paper, unless you have developed a fondness for the taste of toner, in which case, a printed-on piece of paper may be used.
Fold one corner of the paper over to look like the picture below.
Cut off the rectangle of paper that is on the right leaving you with a perfectly square piece of paper folded in half along the diagonal.
Fold one of the corners up as the picture indicates.
Fold the opposite corner up just like in Step 4.
At this point, you will be folding the sides of the cup down. Take one piece of the two flaps and fold it down.
Then, fold the other flap down on the other side of the cup. Now, open your cup up and fill it with water. Drink and enjoy the refreshing feeling of a job well done. Go home early - you have earned it.