Free support is strictly limited for the advanced custom receipt / invoice templates area. The opportunity you have is to fine tune the layout of your dockets, but substantial effort is requried, and it's not for the light hearted.
Essentially you need to craft all the dynamic elements if you want a custom template.
If you make a mistake and want to revert to the original defaul tempate, just delete your custom template and save it blank.
The following custom tags can be used. with square brackets around it.
thanks for your order [ORDERNUMBER]
b_cust_name, b_cust_firstname, b_cust_company, b_cust_address, b_cust_suburb, b_cust_city, b_cust_state, b_cust_postcode, b_cust_country, b_cust_email, b_cust_phone,
b_ship_name, b_ship_firstname, b_ship_company, b_ship_address, b_ship_suburb, b_ship_city, b_ship_state, b_ship_postcode, b_ship_country, b_ship_email, b_ship_phone,
b_cust_notes, b_gift_message, b_confirmTermsAndConditions, b_custom_fields,
Ship Date: [b_shippedon] or [shippedon]
Tracking Number: [b_courier_ref]
Tracking URL: [b_courier_url]
Shipping/Tracking Notes: [b_courier_notes]
Account ID: [mbr_reference]
Member Notes: [mbr_notes]