Rigourously speaking, good mediums are rare. The majority generally,
has one or another defect that takes away from their good qualities.
The defect, as small as it may be, is always of moral origin.
Therefore a medium must have the 5 following qualities to be
considered a good medium: SERIOUSNESS, MODESTY, DEVOTION, SACRIFICE,
SELFLESSNESS.

- From Mediumship without Tears by Eliseu Rigonatii
Seriousness sends the message that one is ready to be of service to a
good cause. Therefore when one has shown through actions that one is
serious about the work, one receives all the help necessary to carry
about the task at hand.

Modesty allows one to work, without thinking too highly of oneself.
Another word for modesty is humility, which is the ability to humble
oneself, to recognize one does not know the answers, that only God has
the answers. Modesty allows one the ability to receive good guidance,
and listen to the voice of the divine. Modesty also allows us to
correct our mistakes once we recognize them, and live a simple life of
service. With modesty we know that we are a simple vessel of the
divine instrument.

Devotion is dedication, which is also practice. This means really
working hard with discipline and with love. It means having the
passion and desire to work hard for that which is really meaningful
and to the benefit of our brothers and sisters. A devoted medium is a
servant of the Lord, for this reason he/she will not waste any
opportunity to be of service to the divine, by helping all needing
help from God.

Sacrifice allows us to renounce the world of pleasure, and the
associated habits. By giving up these bad habits, addictions, we
gather the necessary energy to be truly a good clean vessel. This
energy gives us the vitality and firmness we need to be of service.
Selflessness, refers to lack of self-interest. In a world driven by
self-interest, this is perhaps the most difficult quality. One who
attains this quality is said to receive the gratitude of others. This
means having no agenda.