OP, I too struggle with window reflections. I just shot a few of a storefront. I have no real issues with reflections on the front glass, my reflections come from glass behind the display. This art studio is downtown and on a main street with buildings across the street. I use a CPL on my lens. I just do my best to get the best angle to get the least amount of reflections possible. I have tried pretty much every angle, there's no getting rid of them all. If anyone has any other suggestions, I always welcome them.

That's a really nice Christmas photo.
So how much do you feel the CPL helps? A little, a lot?
This shop sits on a two lane road near the square of my hometown. Street lights, businesses, all causing glare. I often feel like I am battling the reflections as I try to find the best angles to shoot and minimize those reflections!
