Marbling Masking Tape
If there is one thing that separates professional-looking models from amateur-looking ones is an interesting paint job, that has visual information in every place.
This does not mean detail painting every rivet, every inch of it. You can achieve that by layering paints of different shades.
There are many techniques to do so, but possibly the easiest and fastest one is using marbling tape. You will save hours of work and, if you are not an expert with your airbrush, even prevent undesirable results that force you to strip the paint and start again.
Just paint the base color and wait till it dries, stick marbling tape on top, and then paint (preferably using an airbrush) with a slightly darker or lighter shade of the color. You can even be bolder and use different colors and transparencies to achieve super realistic-looking finishes.
We have to prepare each shipment individually as they are ordered, so allow it in 3-4 weeks to arrive in the USA/Canada (to be safe) and 3-6 weeks rest of the world, though they are usually delivered much faster.