This method of breaking a fall is very simple, easy to make and will guarantee(unless you miss) that you won't take fall damage from any height.
Step 1: The X
Place a slab of any kind down.
Step 2: The X
Now place 3 more slabs down so that it forms a "X" or a "+" symbols.
Step 3: The Breakage
Now add water in the center of the X.