Avodah Zarah 7 - How to Petition God
An even stricter prohibition of business before idolatrous festivities belongs to Rabbi Ishmael - three days before and three days after. According to him, doing business with the worshippers of the Sun, who dedicated every Sunday to the God of Sun, is always prohibited.
However, today these prohibitions don't apply, because today's idol worshippers do it only by rote. Moreover, many societies have accepted upon themselves a moral code which differs greatly from the lifestyle that idol worship expressly allowed. To emphasize that, Rabbi Moshe Feinstein called the American society a "Government of Benevolence."
When should one ask for his personal needs, before or after the prayer? Some say, following the example of Moses, that one should start with God's praises, then ask for his needs. Others says that for us to follow Moses would be presumptuous. Rather, we should ask for our needs first, which will lead us to realize that we can rely only on God. We then will be in the proper state of mind to pray, while Moses did not need this preparation.
Art: Jacopo Tintoretto (Robusti) - Deucalion and Pyrrha Praying before the Statue of the Goddess Themis