Hi Phil,
Before you take the shot have you checked your histogram? If all the peaks are pile up to the lefthand side then your shot is going to be underexposed and it will turn out almost black. The other matter is have you waited too long and the light has got too dim to take a shot? The magic hour is the 60 minutes immediately before the official sunset time, when the light has a wonderful quality.
Personally, I would put the camera on a tripod with a remote release and into manual mode. I'd decide what aperture I wanted for a given shot and I would then adjust the shutter speed until on my histogram the highlights were shown to be just clipping the righthand side of it. I'd then know that my shot would be correctly exposed.
Now if the shot was blurred and I had used both a tripod and remote shutter release then I would think that the blurring could have been caused by the vibration of the mirror as it flipped up, so before taking another shot I would lock it up first and then I should capture a shake free image with my next shot.
Hope this brief guide is of some help.