Hello,
You can precise which kind of data you want add to your email, this will allow us to be more specific in our help.
But the instruction is quite simple, but you have a point to know, some tags have to be used only in specific part of the email, let's detail an example :
Ex: {LINEVAR:order.order_invoice_number}
Like you can see, this tag is relative to order invoice number, and can be used only in order part between {TXT:ORDER_BEGIN_MESSAGE} & {TXT:ORDER_END_MESSAGE}
If not, the tag won't be replace by your dynamic data.
Hope this will help you to move forward on your subject.
Regards