There is normal ritual prayer, which is good in its own way. If it is not too mechanical, it can help you get an idea of your own self. God already knows your needs but this kind of prayer, if sincere, commits you in the eyes of God to certain directions. If you are sincere, you will yourself notice that at any given point, prayers for some things are coming out from a greater depth. It is best to leave the things which are not coming from this depth. Leave such things totally to God. Sincere prayer can be understood to be the Will of God. Mechanical prayer is often your greed, or perhaps, habit. It is said that one should pray for even tiny needs but it has also been said one should be patient, that one should be not greedy, one should work etc. Taken together, pray at this mechanical level only when you absolutely must.
The confidence brought on by prayer cannot lead to arrogance in the particular thing one has prayed for. Additionally it is impossible to sincerely pray out of greed, jealousy, desire. Such prayers hardly touch the surface of ones heart.
As long as you rely on yourself you absolutely cannot go deep within into the sacred for prayer. You must become humble at least in that moment. It is strange that such humility should give rise to confidence and without the slightest trace of smugness