I meant any style. I meant any rule, that is more specific then:
,,sometimes it happens.``
Isocrates sounds good. Maybe [Demosthenes, Plato, or Xenofon]'s style would be good as well. It really does not matter as long as it is (a) Attic prose (b) consistent rule set (c) based on real evidence.
(a) can be replaced by any single dialect (prose only) (Poikile Ias, Doric prose (eg. Archimedas), Archaia Ias, Koine, Aeolic dialect), but Attic dialect is prefferable for me, for I do not know enough of the other dialecti.
edit: And yes, I am interested in the rules for prodelision usage as well, though omitting it in the first place. (I could not recall the name of that particular phenomenon)