1. Tap  from the toolbar to select the brush tool.

2. A small triangle in the lower right corner of the brush icon represents hidden tool options. Long press the brush icon to reveal the Brushes panel.

3. In the Brushes panel that opens, you can scroll through a list of default brush types. Tap to select the desired brush type and apply to the canvas.

Note: The brush type used in your previous session remains selected when you use the brush tool again. You can always come back to the Brushes panel and change your brush.

You can adjust brush properties from the floating options panel to suit your creative work.

To bring up the tool options, simply tap the brush icon from the toolbar.

• Color chip: The color chip allows you to choose a color from the color picker, enter a hex color code, or enter numbers for HSB, RGB, Lab, or CMYK colors. You can swipe the color chip vertically to easily switch between the foreground and background colors.
• Brush size: The brush size option allows you to choose the diameter of your brush, which can vary in size from 1 to 1000 pixels. As you vary the brush size, you can also see the brush tip preview beside the tool options bar. 
• Opacity: The opacity option sets the maximum transparency of the color you apply per brush stroke. 100% opacity represents opaqueness. As you paint over an area, the opacity doesn't exceed the set level until you complete the stroke (even when you paint over an area several times).
• Hardness: The hardness setting controls the size of the brush’s hard center. Select a value that is a percentage of the brush diameter. 
• More brush settings: Tap the three dots icon to bring up the settings panel. To learn more about brush settings, see More brush settings.

• Blend mode: The blend mode determines how the active layer blends with the layers below it. Tap the blend mode icon to see a list of available modes. For more information, see Blending modes.
  
• Roundness: The roundness setting specifies the ratio between the brush’s short and long axes. Select a percentage value. A value of 100% indicates a circular brush, a value of 0% indicates a linear brush, and intermediate values indicate elliptical brushes.
• Angle: The angle setting specifies the angle by which an elliptical or sampled brush’s long axis is rotated from horizontal. Select a value in degrees.
• Flow: Flow sets the rate at which color is applied on your canvas as you move your finger or stylus over an area in your document.
• Smoothing: Smoothing produces smoother curves in brush strokes. Higher values apply increasing amounts of intelligent smoothing to your strokes. This option is most effective when you are painting quickly with a stylus; however, it may produce a slight lag time in stroke rendering.
• Use pressure for size: Selecting Use pressure for size varies the diameter of the brush based on the brush pressure applied while painting.
• Use pressure for opacity: Selecting Use pressure for opacity varies the opacity of the brush based on the brush pressure applied while painting.

While using the Brush tool you can activate the primary touch shortcut to access the Eraser version of your Brush, and activate the secondary touch shortcut to switch to the Eyedropper tool.

To know more about how to use the touch shortcut, see Touch shortcuts and gestures.