Web projects pay best when they're billed by milestone — and the invoice should make the milestone unmistakable. This one arrives mid-project: milestone two of three, QA, and launch deployment.
A common shape: 30 to 50% deposit, a milestone payment mid-build, and the balance at launch. Each invoice names its milestone so the paper trail matches the project plan.
As a separate flat monthly invoice — care plans are easier to sell and to pay than surprise hourly bills. Send it on the same date each month; on BillTo Pro, recurring invoices send themselves.
Invoice on your delivery, not their go-live. If the site is built and waiting on their content, the milestone is done. Your terms can say exactly that, and this template's example does.
Fixed for well-scoped builds, hourly for ongoing or ambiguous work — and both on one invoice is normal: fixed milestone lines plus an hourly support line, like the example here.