One simple way to get a handle on 'socket wrench' time signatures is to think of them in one of the usually acctpted conventions of long and short beats--long beat is 123, short is 12.

123 12 12--'long' seven, 12 12 123--'short' seven (usually faster)
123 12--5 (usually Bulgarian or Greek. the opposite is often found in Macedonian music (12 123) The dance known as 'sede danka' is the one in 25/16. 123 12 12+123 12 12+12 12 123 12 12.

And so on. . .

Those are some of the more common ones the casual musician may encounter when sampling Balkan Music, but there are others, some different combinations of compound rhythmns, some are other divisions of 'standard' rhythmns.
I have played a song in 7 that is divided 1+12 12 12--it is Albanian.

It is wise to remember that native Balkan musicians don't think of these rhythmns in 'neat' divisions the way we've been taught to--they often play the long and short beats with varying and different time values--the long beats may be just a little longer or shorter, likewise for the short ones--I've heard rhythmns that seem to contain 'half' beats or *almost* half, or?

It's really very organic.

NS