Yards are one of the most interesting and challenging layout elements to design, specially if you want some switching action that needs more than just somewhere to store a few cars. You mention that you like the idea of having several industries served from 1 track. If you have enough length past the last spotting point (where you would place a car to service the last industry) for a turnout and enough track past that to accommodate an engine with at least 1 car, you can then provide a "run-around" track alongside that service track, so you can pull a car out and return it to the main classification yard (where trains of cars get assembled for despatch), or onto another siding so you can retrieve a car from the next industry that that car was hemming in (assuming that the car/s you were actually after were also blocked from the service sidings main entry.
This is also where a yard lead track is useful. Generally they are outside of the main yard and running away from it towards the opposite direction and often lay alongside the main right o'way. Can take the form of a stub ended siding, or may have a turnout connected to the main at the end. In the latter case, it would sometimes take the place of a main yard, if it were long enough to assemble a train from the industries served. If it lies alongside and connected to the main by a turnout at it's end, the main line can be included into the yard trackage to act as a run-around track for it, under Track Limit rules. Trackside signs are placed alongside the main line to warn trains of the yards existence and yard work crews must keep within those signs, also they must know when to keep the main clear for passing trains.