On this and other pages of wildwinds, where monograms are described, these are "read" as follows, disregarding any issuing magistrate's possible full name, and more or less following the system which Martin Price used in his work on the coinage of Alexander III:
From top to bottom then
From left to right.

This monogram

(on Paris 1972.821) is easy to read because it goes from left to right, reading APAE.

This monogram

(on Paris 1138) is a little more complicated, so we go from top to bottom: O (marked red)-Λ (marked green)-M (marked blue)-I (marked yellow):
so OΛMI.

This monogram

(on Paris 1138I) is again a little more complicated, so we go from top to bottom: P-M-T and then to the right: E, so this is PMTE.

Monograms are not always as clear as they could be, so you often need to look closely.
The monograms on the Sardes club reverse types are usually placed at the base or above the head of the club.
During my research for my 4-volume catalog of Lydian coins, GRPC Lydia, I discovered and documented :
- 85 different monograms on the Apollo/club type.
- 61 different monograms on the Herakles/Apollo type.
- 21 different monograms on the Tyche/Zeus standing type.