Build the aircraft armed and tanked or not?

First off, total newby here. As a kid I would build a kit, no matter which one, totally armed and tanked to the gills. During WWII I would think some aircraft would always be armed? Maybe not. But most modern jets these days would be usually seen with empty pylons wouldn't they? I guess our modeling is like taking a 3-D scale photo of an aircraft at any given time so anything goes. Maybe some Vets would chime in here. Would an aircraft be sitting on the ramp armed to the teeth with engine plugs and pitot covers on? Or bombed up with an engine cover off?