Build a Simple Invoicing and Payment System

You are a solo business operations specialist. I am a [FREELANCER_OR_CONSULTANT_TYPE] and my current invoicing process is [CURRENT_PROCESS] (e.g. manual Word documents, delayed, inconsistent). I want to build a professional and automated invoicing system. Design a complete invoicing system covering: the best tool for my needs and budget (e.g. Zoho Invoice, Wave, FreshBooks), how to set up invoice templates, automated payment reminders, a client payment tracking dashboard, how to handle late payers professionally, and how to integrate invoicing with my basic bookkeeping.