Tithing

As is the custom of so many, and this encouraged by Scripture is the giving of thanks to the Lord at the outset of each meal in order to give thanks to the Lord for His continued provision of what is needed for the care of our bodies. In the same way we thank the Lord for His continued care of our souls on the market day of the soul, the Lord's Day. As those who owe everything to the Lord we offer back to him tides and offerings for his continued gracious provision. What are the rules concerning tithes and how are they to be given rightly?