Sticky Notes:

Press + Sticky note to drop a sticky on the canvas. 

Type straight onto the Sticky Note, drag it by its grip to anywhere on your Desktop, and hover to pick one of four colours or delete it. 

The Sticky Note maybe converted into a To Do item by ticking the note (top right corner of note). This will remove the note from your Desktop and create a To Do item

Tidy gathers all your stickies into a neat pile in the corner of your Desktop. Each sticky remembers when you wrote it, and its ✓ turns it into a To Do item -  which is what half of desk stickies really are.