wind does not "usually" blow in one direction it blows in all directions (direction depends on where you are) and wind has a random direction and speed do to the fact that wind is created through air...
Trade Winds blow fast and in Pretty much any direction. That's why sailors try to sail there often.
east to west
Trade Winds in both hemispheres blow from the east.
Coriolis Effect. Due to the spinning of the earth, it causes eddies at the equator which causes the easterly trade winds.