Use Live Annotations > Chalk Mark Best Practices
  
Chalk Mark Best Practices
When you’ve mapped the environment well enough, you’ll see the following message and can start using live annotations and drawing Chalk Marks.
The first time you use Chalk, make sure you select a color for your Chalk Marks. This makes it easier to differentiate your marks from the person you are Chalking with.
Here a few things to keep in mind when drawing Chalk Marks:
Use simple drawings to communicate instructions.
Circles, lines, & arrows work best.
Delete Chalk marks that are no longer needed to reduce clutter,
Use the pause button to draw on a steady image.