Good UI/UX designers (like Apple have) will classify interactions into: Obvious, Easy, Possible. Take the iPhone camera; Obvious: taking a picture with the sh

Good UI/UX designers (like Apple have) will classify interactions into: Obvious, Easy, Possible. Take the iPhone camera; Obvious: taking a picture with the shutter button Easy: switching between front and back cameras is easy to discover Possible: switching between HD and 4K (in the settings menu - possible to discover. Unless your product is as simple as an office stapler, some parts of it will be non-obvious, that's fine.