Overcast days can produce rather flat light that lacks dimension and can feel rather boring, and as such, it can be a bit tricky to product images that are compelling. That does not mean you should just pack it up and head home, though. Flat light can actually lead to fantastic images, and this excellent video tutorial will show you how to find and shoot them.
Coming to you from Roman Fox, this awesome video tutorial discusses how to handle the flat light produced by overcast days to still produce interesting shots. I actually love these sorts of days. The nice thing about flat light is that with the flexibility of modern camera sensors, you have a ton of directions available in which to take a photo, and you can relatively quickly and easily shape the light in the photo to emphasize in the manner you prefer. This can also make it excellent practice for learning how to work with shaping light in post. When it comes to more defined light, it simply is not possible to reshape the light as much as it is when you are given a blank palette. Check out the video above for the full rundown from Fox.
I prefer overcast to a sunny day from late morning through early afternoon when the sun is high. The even light is better than directional light from high overhead. An exception is late Fall and early Winter. While not real low, the sun is fairly low to the south at midday.