A while back I posted a question on the Rover Trailhead forum about when and where it was appropriate to wear the uniform. I was asking it from the context of the BSA uniform, as there are certain guidelines they have for their uniform. I got a few different answers, but the best one was to wear it whenever I did scouting. It's a good, simple answer that allows me a lot more freedom of when to wear it, especially as a Lone Scout.
So this is my take on it. I wear my uniform when I am going out to do a service project. I may also wear it on occasion when going to church to show my appreciation to my Heavenly Father for the blessings that come from scouting and to show my Duty to God as written in the Scout Promise. Wearing it at civic events, or events that promote citizenship, and events that honor city heroes like first responders, is also appropriate. I also wear it when doing scouting at home with my family, as wearing the uniform is part of the game of scouting and is lots of fun. It just looks good on me too, heh.