We must pray: in the morning, upon awakening from sleep, to thank God for keeping us through the night and asking for His blessing on the coming day. When starting a business, to ask for God's help. At the end of the case, to thank God for help and success in the case. Before lunch, so that God will bless us with food for health. After lunch to give thanks to God who feeds us. In the evening, before going to bed, to thank God for the day and ask for His protection in the night.
For all these cases, the Orthodox Church provides special prayers.