What are the factors to be considered while preparing international sales invoices? Do sales and delivery terms have any effect on the total amount?

Upon preparing any International Sales Offer / Preforma Invoice / Contract, the following has to be cafuly taking into consideration:

1- Goods Specifications : i.e. Raw Materials, Measures or Dimensions,.... .

2- Delivery Terms : i.e. in accordance with the applied "INCOTERMS" term applied which indicates place of delivery, freight & insuance fees.

3- Payment Terms : i.e In advance / Sight Payment / Deferred Payment / Acceptance.

4- Specifying axact expiry date for this price as well as period for shipment / delivery. 

They are: -Price -Date -Tax ID,contact name,address,postal code,country -Phone number -Shippment details for example: shipment ID/waybill number -Ship To -Sold To infirmation _Units/U/M -Description of Goods,shipper snd. date -Declaration Statement - Harmonized trading cide -Additional comment