If your preferred currency is not included with Classic Commerce you can easily add it (and a custom currency symbol) using this code.
This code will another row to the order email table to add in some regularly recurring information about the order. In this example we are including a line about the standard one year warranty.
The custom fields section can be confusing for novice users and the download permissions section is only necessary if downloadable products are on offer. This code hides both of those meta boxes.