I have this visual......

[OilyRascal]

....of coordinating the cut; one hand on board, on hand on saw, and your two other hands to apply power once you're ready. 

A local power miter saw advert. I enjoyed reading:

"I have a 12in Miter Saw. I do not know what brand it is. Everything works except for the trigger. It is wired up so when you plug it in the saw starts running. Works good other than that. asking $35.00"

[kxxr]

I have a shotgun....

[rusty]

That's why you always need a helper.

"Hey, go cut this plank for me..."