Be transparent – Your client wants to know where their money is going, so don't hide or be too general with line items on your invoices, and be prepared to show receipts. Otherwise, they'll wonder if you’re padding the bill. Be specific. For example, instead of listing 'materials' as a single expense, list each one on its own line, such as: paint, nails, plywood, etc.
Due Date: The Invoice Date plus Payment Term Days give you the Due Date, which is in plain English and easier to understand. Having a Due Date on the invoice is a tactful and professional way of making it clear to your customer when they should pay. Bill To: Who this invoice is intended for and their contact information. Product or service details: Specify Description, Quantity, Rate, Amount and Subtotal. The more details you include on the invoice, the better. This way, your client will know exactly what they are paying for upon receiving the invoice. Make sure that your client can understand every item, so that as soon as they receive the invoice, they can pay you instead of asking questions and delaying the process.