So I know I havent posted on here for a long time, but I have gotten the interior and cockpit done, and am now working on the bottom hull painting. I have gotten the bottom primed and painted with DOA paints, and also have the panel shades done. It is time to start the weathering process! This is where I am stuck. I have been stuck at this spot for about 1.5 months now, as I dont really know what to do first!? I know there are washes, streaking, discoloration, rust spots, etc. I am just frozen, as i am overwhelmed with how to start it. First, do I need to varnish it? I bought some satin and gloss Vallejo acrylic varnishes I can spray in my airbrush I want to use. I also have spray can umbrol matte and gloss cans, but am nervous to use those, as my test piece for my matte turned out frosty! I dont want to do that to my bottom hull after all the hours put into it!
I want to try doing some oil washes, and then some discoloration on the panels like Fichenfoo does on his small falcon on youtube. So I am guessing I have to varnish first. But should I use satin or gloss? After that, what steps do I take? It's just so much, that is why I am stuck. Here is a couple pics of the hull as of right now. I do have some extra panel pieces I can practice on first, and plan on doing before hitting the real model!

Awesome! Yes, this is the look I am going for. Your way is very similar to Fichenfoo on YouTube on his smaller falcon. I do have 2 big test panels I am planning on using first, plus an extra lower recess pit to try weathering first before the 2 pits I plan on putting in the bottom hull.
You said you didn't paint the panels first, but mine are already primed and painted with the base coat and panel shades for the bottom hull from DOA paints. The top hull isn't painted, but is primed already with gray primer. So can I use your method on painted panels already? If yes, would I need to varnish the panels first? Thanks, and your model looks awesome!

You need to resize your images to 650 x 480 and not upload from iPad as they do not load well.
I had painted some of the panels particularly on the main engine rear top and used the oils straight on the paint without varnish and was fine. However, I did leave those painted panels to dry for a couple of weeks before doing so. If you have the spare panels, try it first but should be fine.
Once all the weathering had been applied, I let it dry for a few weeks, then applied a matt varnish to seal everything.

Cheers
Mark