A single fold along the long axis of a page. This results in a folded piece that is 8.5" x 5.5".
A single fold along the short axis of a page. This results in a folded piece that is 4.25" x 11".
A diagonal fold across a page. This results in a folded triangle with a rectangle piece to the side of it. This rectangle piece can be cut off to create a square with the remaining paper.
A curled page. This can be one on either axis of the page. This is useful in creating other projects such as the bound book.
Two folds on a page to create a shutter effect with tabs. This can be done by folding a page in half like a hamburger and crease it lightly only to mark the center of the page. Next, unfold the hamburger and fold each edge of the page to the center mark.
Dinah Zike's Five Basic Folds