Ok, Here is what I recon
There are two basic types of sunset shot, in my opinion, and this clearly fits into one of them. The categories are:
1) The shot has a black foreground and relies on an interesting silhouette to provide the focal point of the image. These tend not to have lead in lines as a result of the far gone failing light.
2) The shot has been taken with the use of grads (or other similar methods) and so has details in the foreground.
Obviously, this is a very critical way of categorising, and there are exceptions. However, in this case, your shot falls neatly into the first category.
Now, in general, the first category relies on a very strong and interesting silhouette outline to provide a focal point. Lead in lines are not common here, so the focal point has to be instantly obvious. Here, I feel the scene does not provide this, so scouting a different location might be good.
Assuming however that you want to improve upon this location, there are a number of things you can try. Firstly, use F/8 (which you have already done) but not for reasons of DoF. The foreground is in total shadow, so there is nothing there to be in focus. The tree tops are sufficiently far away to not worry about focusing at 1/3rd into the frame and using the aperture to drag the rest of into focus. Coincidentally, F/8 is generally the sharpest aperture value to use, so in this style of shot, for this reason alone, F/8 is the best aperture value to use.
You said you used a tripod, which is a step in the right direction for sure. If it is really REALLY crap, then perhaps consider investing in one of the cheaper manfrottos... Don't have to break the bank to get a sturdy (or atleast noticably more sturdy) tripod. I noticed you are using a 50D from your EXIF, so using self timer and (if it has it) mirror lock up will help to reduce camera shake when the you take the shot and the shutter actuates respectivly. You used spot metering as well according to the EXIF... I am assuming you took a spot reading from the sky? If so, this is the best way to shots of this style.
So by doing this lot, your shots will be sharper, the sky will be exposed properly and the shot as a whole will not have camera shake. Oh, and maybe compose with the horizon on, if not slightly below the bottom thirds line.
I stand by my original point though of trying to find a better location. Perhaps try and find something where the outlines denote contrasting themes... A tree next to some scaffolding (as a generic example) will contrast not only by the silhouett, but also by the man-made / natural contrast. You kind of have this aspect in this shot, but it really needs to stand out.
HTH!
PS: Shame I'm not still at Exeter uni, we could have met up and had a shoot
PPS: Which reminds me! Perhaps try the same style of shot down by the cathedral... lots of trees down there to compliment the harsh outline of the cathedral. Or, do you know Thomas Hall?
[/IMG]
but my advice would be keep it cool and don't smoke on the job.