I know in rider schools they teach to hold the clutch with the bike in gear, but I'll continue to put it in N. I watch my mirror as often as I can and tend to pull up beside the car in front of me to allow an escape route....
Never at a stop sign or a turn, but always at a red light, I hate holding the clutch lever in, I usually wanna stretch, or reach back and make sure my bags are closed tight. Yes I check them every single time I stop, lol.
Keep mine in gear, unless I need both hands to adjust for something or need to rest them during long rides, but if I do put it in N, it's only after a few cars are already stopped behind me, or I see no one's coming up back there. Oh, and I'm never in N at a stop sign that I can think of.
I will go to N every once in a while if I need my left hand for something, but I like to be in gear, I also pull to the side of the car in front of me in case I get hit from behind. (that will keep me from being a sandwich