Something I have always wanted to try was stacking multiple ND filters during the day time to get a super long exposure. Taking a long exposure in the day is tricky due to the sun and shadowing factors. You also need to have clouds for some movement in the sky to make the picture more interesting and show depth. I found the perfect situation to try this but didn't have much time. I have a 6 stop and and 10 stop filter that I stacked on to each other to get a full 16 stops of light. Moving the exposure to around 3 minutes with enough depth of field caused me to move my f/stop to f/11 and increase my ISO to 400. I didn't want to take a much longer exposure due to the amount of noise that you will already have in your image due to the time and thereat of the day at 3:30pm. The other problem is with 16 stops of ND filter in front of your image, you can't really compose a shot due to everything being so dark. I probably should have composed the shot then added the filters on later, but time wasn't on my side. I took the original photos and worked them as I normally would in Lightroom and was given the suggestion of cropping and conversion to black and white.
This is the first photo I took from the day and ultimately turned out to be my favorite once I cropped and converted the file. I did a massive amount of work on this file to make it presentable and I am very happy how it turns out. This was 217 seconds.