Effects: There is a permanent blending of the influences of stars that are conjunct one's natal planets. When a transit, arc, or progression, conjuncts a natal planet, it will express the nature of the fixed star that are aligned with that natal planet.
Orbs of influence: Nobody seems to know what is the correct orb of influence. There is general agreement that the bigger and brighter stars have a stronger influence than the dimmer stars. Astrologers usually agree on a one degree orb.
Magnitude system: This is a method of expressing the apparent brightness of a celestial object. The magnitude system is confusing to many people, since the magnitude number grows larger as the star grows fainter. The confusion will disappear if the word 'class' is substituted for 'magnitude'. Obviously we would expect a 'first class star' to be brighter than a second or third class star and so on...
Aspects: Robson (The Fixed Stars and Constellations in Astrology) says:
"The fixed stars operate by position and are said to 'cast no rays' or, in other words, their aspects are said to be ineffective and their influence to be exerted only by conjunction and parallel".
Some authorities suggest aspects to the fixed stars can be read, but it is only the opposition that is thought to be of any relevance. The opposition may exert some influence due to the polarity, but the conjunction is by far the primary aspect to consider. Trines, sextiles and squares should therefore be discounted.
The fixed stars are only to be read to the natal and not to the progressed or arc charts.
Fixed stars are irrelevant to the study of midpoints.
Occultation: Sometimes a planet will conjunct a star by both longitude and ecliptic latitude and hence the planet will physically occultate the star. This happens all the time, of course, but much more rarely with the 290 or so named stars we consider of traditional importance. With this type of conjunction or occultation the energy of the fixed star should be far more greatly emphasized.
Dr Gonzales Tamez says;
"A convenient way to study a given star is when the Moon physically occultates it [or even skims the star]. There are certain big stars that the Moon frequently occultates, sometimes once a month for several months in a row, so you can collect a series of observations of the validity of the traditional keywording for the said star. Obviously the same can be said for when a planet conjuncts a zodiacal star both in longitude and in ecliptic latitude, because then the star will shine through with full strength and its nature will reveal itself to the attentive eye. I have found that specific stars tend to project clusters of synchronistic coincidences. Quite often the name of the constellation will play a role, particularly for stars classified in planetary terms as sharing some Mercurial quality. The fixed stars often bring about bizarre synchronicities and clustering of coincidences that may involve the meaning of the star and the constellation it is in."
One reason why people believe the stars don't work is because of the lack of knowledge of their meanings and nature. The traditional interpretations, although they can be very 'spot on', have a tendency to dwell on the negative influences and show a lack of an overall comprehension of their meanings. Hopefully in time and with proper application of empirical evidence we can be more definite about the possibilities within the meanings of the fixed stars.