ok.  valve guides are a major strip-down job, and it's the stem seals
that would need replacing.  assuming this is high mileage, this motor
may just be worn out.

things you can do though include the pcv valve, check timing [too
advanced = too hot & more oil vaporization] mixture [excess fuel dilutes
the film on the cylinder walls], etc.  try a different brand of oil too.
 some of the cheaper stuff doesn't do much for the engine seals & you
lose oil that way too.  i like castrol as it stopped leaks on my car,
but ymmv.