Currently I am relegated to the position of armchair modeller for space and financial reasons, but I have begun saving towards the goal of beginning construction on a layout next year. To that end, I want to have a reasonable idea in mind of the layout I intend to build (or at the very least a couple of strong possibilities) so that I have something to think about and plan over the next year.
I am reasonably settled on the idea of working in N scale as although I don't know exactly where the layout will go, I can be reasonably certain I won't have a gigantic area to work with and I think that (given the types of scene I want to be able to replicate) any larger scale would not work well. My interest is primarily freight traffic, and I want to be able to run reasonably prototypical mixed goods trains as well as block trains of a good length carrying as wide a variety of cargo as possible.
I have zeroed in on two particular periods of interest. The first is the early 1960s - on the steam side I most enjoy large freight locomotives, and I like the silhouette of many of the Type-1 diesels that were operating in the period so from a traction point of view things work quite neatly. The second point in time that interests me is the era of BR sectorization - I enjoy the various grey liveries that were applied to freight locomotives during the period, and it seems this is about as recent as one can go and still have mixed goods while remaining accurate to the prototype. I am leaning towards the former, but thus far information on the latter period has been easier to come by at my local library, which is of particular significance since I'd like to learn the art of scratch-building rolling stock eventually.
The second dilemma facing me is what to model. I'm likely going to choose something freelance but based on one or more prototypes for flexibility, and I think a significant main-line section is a must in order to allow running any period-appropriate variety of train that takes my fancy. My current plan is to have a diagonal main-line section joining opposite corners of a roughly 12'x2' baseboard with fiddleyard connections at either end and then some kind of facility on one side to add operational interest. The question that then arises is what said facility should be - which is an answer that probably differs depending on which of the two time periods I settle on.
The 'obvious' answer for varied freight traffic is a marshalling yard of some kind, but that seems like a very obvious choice and I'd ideally like to do something a little more unusual if I can. I'm hoping people might have suggestions for something else I could do as an alternative that would still generate at least a couple of different types of wagon but manage to be a bit more unusual while doing so.