Design controls for easy operation ✎

The contrast of icons and graphical objects is just as important as that of text. Use sufficient contrast for all elements on the screen, with a minimum contrast ratio of 3:1.

All operations must use simple gestures that need only a single touch. If the site or application does use multi-touch gestures, be sure to also provide simple interfaces. 

Ensure that functions that are triggered by moving a device or by gesturing towards the device can also be operated by more conventional user interface components.

Placement of controls affects their ease of use.

Interactive elements should not be difficult to select or activate when using a mouse or a touchscreen.

Generous sizing and spacing is important, and their implied visual “hit area” should correspond to the control’s active area.