  Although the methods of calculation of power corrections in QCD sum rules are
well known, algebraic complexity rapidly grows with the increase of vacuum
condensates' dimensions. Currently, state-of-the-art calculations include
dimension 7 and 8 condensates. I summarize and extend algorithms of such
calculations. First, I present all the formulae necessary for application of
the systematic classification of bilinear quark condensates proposed earlier,
and extend this method to the case of gluon condensates. Then I apply these
systematic procedures to expansions of bilinear and noncollinear quark and
gluon condensates in local ones, and of noncollinear condensates in bilocal
ones. The formulae obtained can be used for calculation of correlators
involving nonlocal condensates, and for inventing consistent anzatzs for these
condensates. Finally, I briefly summarize the methods of calculation of heavy-
and light-quark currents' correlators. This paper is aimed both to present new
results on gluon and nonlocal condensates and to be a self-contained handbook
of formulae necessary for calculation of power corrections in QCD sum rules.
