Draw and paint in Photoshop on the web

Select the Brush tool (B) from the Paint nested tools in the toolbar. 

In the toolbar, use the color picker to set the color you want to apply while applying brush strokes to your image.

In the tool options bar, select from a list of brushes in the Brush presets drop down menu. Also, you can click the three-dots icon in the Brush presets panel to Manage brushes or Reset to default brushes, and click the + icon at the bottom to Discover new brushes or Import from files.

Further, you can set your desired Brush size and Brush hardness, and Flow which determines the rate at which color is applied on your image.

Select the three-dots icon to access more tool settings. In the More options panel that opens, you can select a Blend mode from a list of drop down options. Blend mode determines how the active layer blends with the layers below it.

Move the respective sliders to set the following properties:

• Opacity: Controls maximum transparency of the color you apply per brush stroke. 100% opacity represents opaqueness.
  
• Angle: Specifies the angle by which an elliptical or sampled brush’s long axis is rotated from a horizontal. 
• Roundness: Specifies the ratio between the brush’s short and long axes. A value of 100% indicates a circular brush, 0% indicates a linear brush, and intermediate values indicate elliptical brushes.
• Smoothing: Smoothing produces smoother curves in brush strokes. Higher values apply increasing amounts of intelligent smoothing to your strokes.

You can also toggle these options on/off:

• Use pressure for size: Enable this option to vary the diameter of selected brush based on the pressure applied while painting. 
• Use pressure for opacity: Enable this option to vary the opacity of the selected brush based on the pressure applied while painting. 

Click and drag anywhere in the image to start painting.