Hi Chris, here is one way it can be done -
The line on top with the pressure gauge is the fuel line. Each carb has two inlets on each end of the carb, primary and secondary.
Just below that is a solid silver bar connecting the throttle linkage from both carbs together.
Below that is the throttle cable, one is shown halfway on the linkage bar, while the other is shown on the rear (right) throttle linkage (with a black end cap).
The last important item is the throttle return spring, mounted on a throttle linkage and intake.
The carbs in the picture are mechanical secondaries, so no need for vacuum hoses.
On the other side of the carbs would be a choke control, either electronic or manual.
Electronic will have a wire running to a small verticle canister just forward of center.
Manual would have a cable running to a bracket just forward of center.
That's your basic dual carb setup. The rest of the engine can be detailed as any other.
Hope that helps a little.