I do models of stuff that was previously designed for sand casting processes, then we send them off to a foundry, and I'm not familiar with their CAD processes.
Knowing a little bit in general, I would say that they might have to scale the model because some metals shrink significantly as they cool. I've used the scale tool to do this, though often they just send it back and ask that my part be desired net size.
Draft (a setting on extrude) is directly applicable, as are ribs, but I don't remember having one work just the way I wanted it to.
Castings with cavities in them have cores, which the foundry has to make. I haven't done this but I imagine if there's not a button that does particularly that, you might bound the cavity with surfaces, trim, fill and then knit them together to get the shape you need to define the core.
Even though the models can be really complex the first few +ive and -ive features on the toolbar get by far the most use from me, extrude, revolve, loft. Shells start out really easy but IME they don't play well with the boolean tricks and this cuts that things that I need for the proper net shape.
One often overlooked but really useful tool for complex models is the rollback bar. If you forgot to put a feature in the right order, or need to change when it comes in the rollback bar is your buddy.
There are little tips and trick to use to get your lofts to work (one thing to remember is SWX wants loft sections to have the same number of nodes, you can split a straight or curved line of the sketch to make it this way and thus make SWX happy)
