Two other techniques you can apply is the filter and the "dot" filter.
A filter is similar to a wash in that it is super thinned paint that you apply to a large area, the difference is a filter is thinned so much (90% thinner to ~10%paint) that it looks like tinted thinner. It's the same principle of photographers using colored screens to alter photo colors, use different colors like blue, red, brown, etc give subtle tonal variations in the paint scheme, which is how real paint looks. You can even apply them to one panel to differentiate it from the others. Just use a wide brush and quickly brush the area to be "filtered".
The other technique is the "dot" filter. For this you need some oil paints of various colors. On my huey I used blue, yellow, tan, red, etc. Take a pointy brush and put dots of paints in different colors in random patterns on the target area (it's better to do smaller areas with this technique instead of trying to do the entire kit at the same time). Next take a wide brush dipped in clean thinner and blend the dots down. Keep blending them down, stopping to clean your brush and get fresh thinner, until most of the paint is gone. Then move on to the next area. It sounds silly, but this technique will give you very realistic looking paint jobs.
If anything isn't clear let me know and I'll try to explain it better. Happy weathering!