Can't wait to see the answers to this question. I have never heard about it, I think its a Roman practise. So, I think you wont find it before the Roman conquest of Macedonia...
In Justin's epitome of the history of Philip II of Macedon by Pompeius Trogus, Pausanias, the assassin of Philip, is said to have been crucified. An earlier account has him speared by javelins.
A. B. Bosworth, “ Philip II and Upper Macedonia” CQ 27 (1977), p. 94 n. 1, does not entirely exclude crucifixion, acknowledging that “the consensus of evidence is that Callisthenes died in this way (Plut. Al. 55. 9 Arr. 4. 14. 3 (Ptolemy))”. As will be raised in the paper I am writing on the assassination, it is it is possible that Pausanias was crucified after death as a public humiliation and warning.
Right now, I would just be interested to know if there are any other examples of Macedonian use of crucification as a means of execution.
The execution mode applied to political and religious crimes, like hemlock, was with precipatation, those outside of Athens applied to Sparta, Delphi, Corinth, and Thessaly, the convicted was pushed from the edge of a high cliff to cliff in the pit or trench in Athens, Keadas in Sparta, in Crows in Thessaly. The Athenians in the 4th century eg using the "apotympanismo" apotympanismos equivalent to death on board(Αριστοφάνης Θεσμ. στ. 938, 942, 1028: προς θάνατον δείται έπί της σανίδος. Ήρόδοτος 5, 72: την άπί θανάτω κατάδεσιν). see bibliography Α. Κεραμόπουλλος, Ο αποτυμπανισμός, Αθήναι 1923 (in greek)