Here are a few easy ways to remember 4 charan lords of all 27 nakshatras or lords of 108 nakshatra charans.
Nakshatras
Charan I
Charan II
Charan III
Charan IV
Ke
1, 10, 19
Ashwini, Magha, Moola
Ma
Ve
Me
Mo
Ve
2, 11, 20
Bharani, Poorvaphalguni, Poorvashadha
Su
Me
Ve
Ma
Su
3, 12, 21
Krittika, Uttaraphalguni, Uttarashadha
Ju
Sa
Sa
Ju
Mo
4, 13, 22
Rohini, Hasta, Shravana
Ma
Ve
Me
Mo
Ma
5, 14, 23
Mrigashira, Chitra, Dhanishtha
Su
Me
Ve
Ma
Ra
6, 15, 24
Aadra, Swati, Shatabhisha
Ju
Sa
Sa
Ju
Ju
7, 16, 25
Punarvasu, Vishakha, Poorvabhadrapada
Ma
Ve
Me
Mo
Sa
8, 17, 26
Pushya, Anuradha, Uttarabhadrapada
Su
Me
Ve
Ma
Me
9, 18, 27
Ashlesha, Jyeshtha, Revati
Ju
Sa
Sa
Ju
Further simplification gives the following table:
Nakshatras
Charan I
Charan II
Charan III
Charan IV
Ke, Mo, Ju
1, 4, 7, 10, 13, 16, 19, 22, 25
Ma
Ve
Me
Mo
Ve, Ma, Sa
2, 5, 8, 11, 14, 17, 20, 23, 26
Su
Me
Ve
Ma
Su, Ra, Me
3, 6, 9, 12, 15, 18, 21, 24, 27
Ju
Sa
Sa
Ju
We know that for kalapurusha kundali, Ma is the 1st house lord, Ve is the 2nd house lord, Me is the 3rd house lord and so on. So, even further simplification yields the following table:
The following points need to be evaluated for a good astrologer:
Mercury, Jupiter give the capacity to learn & advise. Mercury gives mathematical ability also.
Saturn, Rahu, Ketu, Venus give the inclination to venture into metaphysics.
Uranus is considered very important in KP & western astrology for a good astrologer as it has connection to space research (Uranus represents Aquarius in western astrology).
Moon is important as Moon represents mind and astrology is a lot about psychology. Also, Moon can give psychic ability to an astrologer helping him/her in predictions.
2nd house gives the potential to study, research, accumulate knowledge and for spoken words.
3rd house of consultation/upadesha.
8th house gives the inclination to delve into hidden, mysterious and transformative things.
If 5th and 9th houses are prominent, the astrologer can have spiritual understanding also giving him/her wide perspective.
Presence of fire element, as fire element gives problem solving ability. This can be checked via fiery ascendant and/or fiery grahas etc. Mars gives rational mind that likes to attack problems due to fiery nature and hence is particularly useful.
Prominent 10th & 11th houses point towards success but this is true in general and is not specific to astrology.