When I am drawing in PowerPoint or Google Presentation sometimes I need to nudge a shape over, but the arrow keys nudge it over too much.

Hold down the shift key while using arrow keys and your object you are trying to move will move one pixel at a time to help you get precise placement.

Another drawing trick is when resizing pictures by grabbing the corner, hold down the shift key and it will constrain your  proportions.  This helps keep your picture square and your circles round.