Acharya Indu Prakash in vastu shatsra talks about keeping some important items in the temple. Apart from the pictures or idols of God, worship material and some books of worship, no extra material should be kept in the temple as it can have negative effect.
A red colored cloth should be laid before placing photographs or other idols in the temple. Never keep lamp or any other item of puja on the ground for worshipping. Always keep the lamp on top of rice or in a plate. Apart from this, one should never worship two conches, two suns, two lingams, three Ganapati and three Durga idols. This can be harmful for you.
Also, keep in mind that in the temple, install the idol of Lakshmi ji on the right hand side of Ganapati and the left hand side of Shri Vishnu, i.e., install the idol of Lakshmi ji between the idol or picture of Shri Vishnu and Shri Ganesha.
