Here’s a tip for making something look gigantic: exaggerate the contrast between large, soft forms and tiny, sharp details.
For example, in this pencil sketch of a B777-200 yesterday, I peppered the big sausage shape of the fuselage with lots of tiny accents, all the way down to the rivets around the cockpit windows. (Click to enlarge.)
For a drawing like this, you’re not necessarily aiming for an obsessive level of finish. Instead you’re emphasizing extreme contrasts of scale and ignoring the middle-size shapes, such as the service vehicles.
I used a cardboard stomp to soften the big shadow shapes on the ground and on the underside of the aircraft. And I kept the HB pencil honed to a needle-sharp point.
It looks like I'm sketching Jeanette's portrait here, but actually I'm looking past her out the window.
Photo by Little Nandi.com. Travel note: We're in Newcastle, U.K. now, a lovely city of honey-colored Victorian buildings left over from its industrial heyday. The architecture should make good watercolor sketching on Friday if the weather permits. Friday night the city transforms with its legendary "stag and hen" revelry.