Drag the screed board (a 2 x 4 or similar piece of material) across the form boards that line the slab to bring the cement down to the correct level.
Attach as many extension pieces to the handle of the bull float as needed to reach the farthest parts of the slab.
Spray the surface of the wet cement with water from the hose.
Draw the bull float across the slab to yourself, starting at the farthest point from yourself.
Continue smoothing the surface by repeating step 4, spraying more water if needed to help smooth and guide the float.
Continue in this manner until the slab is completely smooth.