So, you have your data. The first step is to compile it so you know what you're working with.
Most of you have chosen to collect multiple datasets in parallel - you'll want to compile that separately (even though it was collected during the same test).
If you do this step diligently, you'll save time in the long run. Make it easy to read and understand.
If you're doing this step with the help of some fellow experts (recommended), it's time to look at what your data actually tells you.
If you have a good sample size, and tight controls, it will be pretty apparent.
On the other hand, if your sample size is too small, or your variables too... variable, it will be hard to draw conclusions with confidence.
Even a large sample size can create the illusion of fact
Listen, you're not doing hard science. But understand that people will ask you hard questions about why you're coming to your conclusions. And if your conclusions are wrong, you'll have to answer for that.
People aren't looking to you for maybes - maybe it was the browser, maybe it was the device, maybe that user was really tired - they want answers. Specific answers. 'If you change the order of your menu items, conversions will go up 10-12%' answers. And they want those answers to turn out to be right.
A usability report is, at it's best, a plan for action. Make the case for your recommendations.
Via https://uxdesigntemplates.com/resource/user-testing-report-template
Being informal doesn't mean being lazy. It's actually more difficult - you need to explain thoroughly, but in simple terms, and in a way that's easy to synthesize.
You're telling people how best to spend their money. Think about what they care about - what works, quick wins, and big wins.
That being said, if you want a jumping-off point for a more formal documentation format, here's a couple:
You know a lot already. It won't be long until you're working with someone who knows less than you. They will probably be your boss.
You'll learn that when you're in a room full of developers, you'll argue differently.
You will know how to solve problems. You will know the cutting edge of technology. You will feel the inefficiencies start to weigh on you.
What will you do when you're the only person who knows how to make a website accessible?
What will you do when you're the only person who cares about responsive design? Or load times? Or security?
You need to make it so your team understands
You need to make it so your boss doesn't need to understand.
If there are improvements you can make within your team without additional resources, present it as an opportunity to make your lives easier, and/or grow your skillset.
But remember, anything that starts with 'If everyone would just...' isn't a solution.
Peer review, linting, automation. You need to get your team to agree to be held accountable.
Time to start! ... or is it?
Your reading this week is https://webaim.org/projects/screenreadersurvey7/
If you have headphones with you, please read it with either NVDA or >VoiceOver. Or choose another!