It kind of depends on where it is leaking from.  Visual inspection of the
engine, top and bottom, can maybe help you to zero in on the source of the
leak.  A clean dry paper towel can be used to spot check for fresh oil, a
sign of a leak.  "Driver's side-ish" can be almost anything.  If the crank
pulley is wet, maybe the crank seal is leaking.  I like the valve cover
gasket as a source of a leak, because it is easy to fix.  Unfortunately, not
all leakers subscribe to that philosophy.

Earle