I've used hedge trimmers also but generally lay the bat on a 2by4 and press another one down on top and cut with a razor knife(keep a sharp edge on it or it will tear the paper)(cutting from the unfaced side seems to cut better but I usually have it laying with the paper up). Start the batt in at the top and staple and a pair of scissors with as long a nose as possible works good for cutting out those notches around boxes.
I staple the wings to the studs. Some who still glue their drywall, staple the wings to the inside of each stud leaving an indention there. A razor knife or scissors will cut a slit halfway through the backside of the insulation for placement over sheathed electrical cable cable with the sheathed electrical cable sliding right into the slit. Don't forget long sleeves and a paper mask over your mouth if breathing insulation bothers you.
If you want it to look like a lot of professional jobs I see, hang it with the writing upside down. LOL I guess some don't care since it gets covered up but it makes you wonder sometimes.