Last weekend, I took a road trip to western Michigan, along the lake. Besides needing a couple days away, I hoped to catch a couple of the many lighthouses in the area during rough weather that's common this time of year. Well, that plan didn't work too well except for the first day, but there are plenty of wineries in the area too ;) !
One in particular that I wanted to visit is in Grand Haven and shown below. I got there just as the sun was setting, and had to set up quick to get the first shot. This was of course followd by driving through town like it was Le Mans... Thinking about exposure, I knew I would have to underexpose to get a good silhouette out of the lighthouses and not blow out the sky. Also leaving it dark would saturate the colors. I used a spot meter and measured just to the right of the tower on the right and set it at +1, and got what I wanted.
For the second shot, I did the same measurement for a different reason - I wanted the last light in the sky to have saturated color, but an overall fairly dark scene. Having shot like this before, I knew this would give me what I wanted. Here, keeping that light in the sky was most important and I'd let everything else fall where it did. Both are digital, but I would have shot slide film the same way - I did actually, haven't had the film processed yet though.
Obviously the exposure time was much longer with the second shot, because the light level was so much lower - even both images are a little dark. My point is, don't be afraid to experiment with exposure - there isn't necessarily a right or wrong answer to how you meter a scene, and if you always rely on matrix/auto then you won't know the results are determined.