Nice post, William.
Just want to echo the idea of using live view. On the Pentax K-x that's my go-to (it's an older, 12mp thing) I can magnify the live view up to 10x and really get a clear look at the focus. Although I normally focus manually when using live view. On the K-3 (the one that dirt uses), the live view is even more advanced; not only can it magnify, but it also shows exactly what part is in focus (by adding a little bit of white to the focus parts - we call those the "jucies" - and place the jucies on the part of the shot that will be in the most focus).
The other thing that's important for shooting long exposures (from a tripod, I hope) is not moving the camera when you click the button. I get the best results using a 6 dollar, generic remote from Amazon (I think they have something similar for Nikon) - but I've also done okay using the 2 or 12 second timer on the camera. Tho if you're shooting with a rail, even the slightest bump when you depress the shutter button can mess things up.
