invoice

I've been freelancing for ~20 years. I have a Google Drive template that I use. Then for clients I copy last month's invoice for the new month, add in whatever info I need to (usually very little) and save it as a PDF to email them. Once a month I create and send these invoices to a handful of clients. I also wrote https://github.com/nickjj/invoice to automatically tally up how much I should bill each client. All in all I spend about ~10 minutes a month creating invoices.

Too many to list here, but one of my most useful ones is a Python script to help pay out affiliates. It crawls through monthly CSV files provided by my payment gateways, finds sales and returns by a specific affiliate, calculates what I owe them and returns a dollar amount, a sales break down for each course, how to send it (paypal, wire, etc.) and who to send it to. It's nice because it takes around 2 minutes to payout everyone each month with a very high confidence level in the results. Prior to the script, it was a stressful work flow with many chances of human error. I only did it once before automating it. Another script I use helps me invoice my freelance clients each month. It's a Bash script and is open source https://github.com/nickjj/invoice. It saves me a ton of time every month since I can calculate how much I need to invoice