When drywalling, do the pros cover electrical boxes, or work around them?
I am a general contractor and I'm having a house redone right now after the electrician and plumber roughed in. I tape off the plumbing and stuff newspaper in the electric boxes and light fixture boxes. When the mudding is done and they do the finish, I'll go around and remove the newspaper and clean up the boxes. 

This takes about an hour total time and sparkey and plumber will love you for it. If it's a time and material job, you will save a couple of hours on both subs, so it's a big payback.