Small mistakes in the temple of the house can cause you great harm and are also very inauspicious.
Always keep in mind that there are no fragmented idols or photographs in the temple
During the puja one should not keep the conch shell in the temple. If there are 2 conch shells in the temple, remove one.
Never keep Shivling in the house and also do not keep more big idols in the temple of the house.
There should be a statue of Ganesha in the temple of the house, but there should never be 3 idols of a god.