CTRL + SHIFT + A
deselect all
For copying colors use the eyedropper tool.
To duplicate drag the mouse with ALT
pressed and
mouse cursor hovering over the object in question.
When exporting, check Use Artboards
to cut off any
vectors that are a little bit off the canvas
CTRL + SHIFT + V
paste in the same spot as the source object.
CTRL + ALT + SHIFT + D
transform each
When changing the path direction (e.g. when working with art brushes), when selected click with the pen tool at one of the ends of the path, try both; then cancel making new path segment
SHIFT + PageUp/Down
next/previous artboard
If you can’t make a clipping mask inside of group, just un-group things and try again