I've been only working with NVDA so far. I highly recommend this NVDA Cheatsheet [3] to get a quick overview. It's also important to test NVDA with Firefox, as it has a better compatibility and thus it is the more common setup for users relying on a screen reader. Look into the difference between "Browse Mode" and "Focus Mode" (briefly explained in the cheatsheet) and how to switch between them. In the Focus Mode you can just tab through all of your focusable elements and check if the announced texts are understandable and no information is missing. In Browse Mode you go through all of the non-focusable content, and again, check if the output is clear and no (implicit) information is missing. This applies especially to all custom components which may announce gibberish if not handled correctly. Finally, you can look into my slides and examples for my "Accessible Web" talk [4].
[1] https://www.apple.com/de/accessibility/mac/vision/
[2] https://wiki.gnome.org/Projects/Orca
[3] https://dequeuniversity.com/screenreaders/nvda-keyboard-shor...
- view your site in lynx
- try and navigate around it with only your keyboard
- try navigating around it using your OS' screen reader