Here are some of our "top tips" for inducing Bugs. Please use common sense when submitting Bugs, e.g. a website will of course not work while you are offline.
In general
Try to cover all different kinds of functions the software has to offer (unless they are mentioned as “out of scope”).
Scan every page from top to bottom to make sure you don’t miss out on anything.
Look for “special” content types like videos, slide shows, streams, maps. These tend to be especially prone to Bugs.
Save progress, close software/log out. Was everything saved correctly?
Use multiple filters and observe whether the results make sense.
Take different paths, don't only navigate one way, i.e. pretend you changed your mind, go back, try something different than before.
Try anything that a user might do.
In apps
Change from portrait to landscape mode
Minimize app and use a different application (e.g. music player, browser)
Turn Wi-Fi and data connection on/off
Activate Airplane Mode, GPS and Bluetooth
Receive a call and text message while using the app
Play music (downloaded, streamed and via the radio) on the device while testing
Switch your device off and back on again
Use Tethering
Go to an area with bad signal, e.g. the basement
If GPS is part of the functionalities, change your location