What is the best way to pray for others?
First, before you even start praying, you should invoke the presence of the Supreme. When you invoke His presence, He will definitely come in a subtle form. You will not see Him in a human body, but you will be able to feel His presence. Inside God's presence, try to see and feel the person for whom you are praying. If you can invoke the Supreme's presence and feel inside His presence those for whom you are praying, that will be the most effective way of helping them through your prayer.
But before asking the Supreme through your prayer to help someone, first ask Him whether you are supposed to pray for that particular person. If you get a message or inner feeling that you should pray for that particular person, only then should you do it. Suppose somebody is very sick and you want to pray to God to cure him.
You have to know that perhaps God wants him to have this experience right now for his own inner development. You have to know that God has infinitely more love for that particular person than you or any other human being could possibly have. If you ask God to cure him, you may only be opposing God's Will. But if you pray for oneness with God's Will, then God may say, "You have become one with My Will. Now I will be happy if you ask me to cure the person."