A clean flasher is a happy flasher.
I'm happy to report that my tiny USB front blinkie was clean as a whistle, so I had time on my hands to write this piece of wholly unsolicited and likely unnecessary advice.
Clean your bits
By that I mean the small things on your bike like your lights, seat bag, computer mount, seat clamp, and, importantly, brake pads. When it's cold and dark bikes are less likely to get washed frequently, and damp, gritty roads mean that abrasive buildup in nooks and crannies. Over time, this stuff can mar your frame and wear your braking surfaces. That hissing you hear as you come to a stop is the sound of your dirty brake pads eating your precious wheels. Get a damp rag and take a few minutes for the small stuff.