WHERE TO CHANT
Chant japa in a transcendental place or near the Deity of Lord Sri Visnu (Krsna).
TONGUE CONTROL
eat small amount of sweets or steaming hot deep fried preparations, and avoid any food which agitates the senses.
"Those who claim themselves to be devotees should eat their meal in the afternoon, consisting of vegetables and different kinds of fruits, roots and grains."
PROPERLY CHANTING ON BEADS
"One who chants on the beads properly, I (the Supreme Personality of Godhead) think of this intelligent person for thousands of years."
JAPA BEADS
The beads which have 108 seeds (beads) are said to be of he topmost quality.
Beads made out of Tulasi wood seeds is said to be fulfilling all kinds of desires in every activity or function.
The mala which is made out of Tulasi wood seeds is said to be certainly rewarding liberation.
CHANTING JAPA
Keeping the beads on the middle of one's ring finger,
One should chant loud enough to hear oneself.
One should not keep beads on the pointing finger and chant japa. Chanting japa with the pointing finger has been rejected.
One by one, pulling the beads inwards and chanting japa is recommended. One should not jump over the head of japa beads.
Otherwise he will not get the results of his chanting.
MORE RULES
One should not touch his beads with the left hand
nor make them fall from the hand.
CHANTING JAPA BECOMES FRUITLESS IF
somebody chants in an impure condition,
with dirty hands,
without a seat,
in a nude condition,
with a covered head,
while talking prajalpa.
Therefore one should chant japa carefully.
Furthermore, one does not receive the perfection of chanting if he chants while:
lying down,
talking,
walking,
standing
on a path
sleeping or thinking about some object,
hungry,
while stretching the body,
while having hiccups,
while mentally disturbed
without counting how much he has chanted
DO NOT CHANT JAPA
while on a path,
in impure places such a crematoriam or in dark areas
wearing shoes,
climbing on a carrier,
spreading two legs,
sitting on an impure asana,
While chanting one should not let one's leg climb another leg and arm climb upon another arm.
While chanting, one should not shake his neck or head, and not to show one's teeth to others.
If one chants japa while keeping his japa beads outside of his bead bag, then his japa is forcibly stolen by semi-demigods, demons, ghosts, perfected living entities from Siddhaloka and Vidyadharas, the dancers in the heavenly planets.
Therefore one should not keep his beads outside of his bead bag.
WHAT TO DO IF YOU BLEW IT:
If somehow, due to certain circumstances, somebody breaks the stated rules to chanting, then he should chant a Visnu mantra or remember the imperishable Personality of Godhead, Sri Visnu.
(Editor's note: In our case, Prabhupada has given us the Panca tattva mantra and also says to just keep on chanting.)
REGULAR CHANTING
If one chants japa regularly to please the Supreme Lord, then the Supreme Lord, being pleased, will increase one's spiritual advancement and give one the eternal liberation.
Srila Sanatana Gosvami says in his Digdarsini-tika that eternal liberation means achieving the eternal abode of the Supreme Lord, Vaikuntha dhama.
Srila Sanatana Gosvami also says that according to one's capacity, one should regularly chant a fixed number of rounds each day. "One should not chant less or more japa day after day". When the fixed number of rounds is completed one should finish chanting japa and engage in other service.