  We discuss $1/Q$ corrections to hard processes in QCD where $Q$ is a large
mass parameter like the total energy in $e^+e^-$ annihilation. The main problem
we address ourselves to is whether these corrections to different processes
(concentrating for definiteness on the Thrust and the Drell-Yan cross section)
can be related to each other in a reliable way so that the phenomenology of the
$1/Q$ corrections can be developed. We derive first the relation valid to
lowest order using both the renormalon and finite-gauge-boson mass techniques
to check its independence on the infrared cut- off procedure. We then argue
that the $1/Q$ corrections are due to soft gluons which factorize into a
universal factor such that the lowest order relations are preserved in higher
orders.
