If you’ve got a character speaking a line of dialogue and also performing an action, don’t get into the habit of always putting the action into a participial phrase tacked on after the dialogue tag:
“This is an important announcement,” she said, taking her place at the podium and opening her notebook.
No. It needs to be either:
“This is an important announcement.” She took her place at the podium and opened her notebook.
or
She took her place at the podium and opened her notebook. “This is an important announcement.”
Save the participial phrases for occasions when the dialogue and the action are truly simultaneous:
“Listen up, people!” she snapped, slamming the notebook down on the podium.
or when the action’s mostly a bit of stage business, there for characterization or setting-establishment or pacing:
“Listen up, people,” she said, shooing away a moth that was trying to fly into the Coleman lantern.
(Who gets to decide what’s important and what’s stage-dressing? You do. It’s your story. Just remember to keep on listening to what it’s telling you. And remember, audiences like variation.)
Dr. Doyle's Blog 
This is a wonderful little piece that teases out the subtle difference between action and dialogue – thank you.