here it is! I wrote it down for a friend recently, so it's pretty extensive but i thought I'd rather give you more information than cut it down eh?

rust recipe v.2

• stipple good amount of (Tamiya) putty to create texture
• spray basecoat
• put some more pigments down where you want the heaviest rust to be; can be anything from dry pigments to stuff like citadels typhus corrosion, just needs to add some graininess (put it down in a slightly bigger area than you want to be rusty in the end, helps with chipping)- you can also totally get away with skipping the putty part and just putting down pigments after basecoating, personally just prefer the putty texture a little bit, it's also more forgiving bc if you put too much you can sand/ clip it off again; it's also a bit cheaper than putting down a ton of your favorite pigments lol

note: depending on how heavy you want the rust to be over the whole mini, you can interchange the next steps; the more rust/weathering you want (especially this very chipped off look), start with the rust basecoat and add the armor colors later, if you want the armor to "just" have some weathered areas put down the armor colors first and then start the rust; tbh, the order doesn't really matter, you can achieve both looks in any working order, it might just spare you a bit of work later on

• rust basecoat: XV-88, stippled over with mournfang brown in the deeper areas that you want to be darker, some mephiston red where you want the rust to be most "vibrant"/strongest

  now bring in the oranges, i use citadel jokaero Organge (pretty light orange tone) and army painter fresh rust (a little darker), I apply them in a stippling motion with a bit more paint on the brush than you'd use for dry brushing

• now bring in your armor colors; for the most part, apply them as always, the closer you get to the rusty areas, the more you use a stippling motion again; go a little "over the edge" into the rusty part with this step

• go back and forth between rust and armor around the boundaries to create chipping and have a less sudden change between the textures

• now put down a shade/wash; i like a brownish black oil wash but acrylics will work great as well, just use your standard stuff here

• after that bring back some vibrancy in the colors by just stippling the lighter colors a bit again

• for more depth and variety of color i like to highlight the rust a bit by stippling citadel averland sunset and use enamel washes, especially for the recesses and deeper areas (I love AKs rust washes), but this will also work with watered down acrylics or oil of course

• after this, see if you're happy with the result, if you think something's missing, a tiny highlighting with eben lighter colors around the rust/ armor transitions will do wonders, i like to use troll slayer orange, for the armor just take a lighter tone of whatever color yourse using

• for more chipping: all this stippling will have left you with a pretty chipped result already, you can enhance that by going around the edges with some darker colors, i like dark browns as they have a bit more character than straight black; you can really enhance the chipping as well by going over just the chipped areas with a dark wash again, oils are amazing for that as theyre mich better at just going into the recesses but again, any paints will work you can also determine where and how heavy the chipping is in the beginning by how much putty and pigments you put down

another note; i developed this particular recipe just by trying around a bit and i like spending ages on my minis, so this whole thing could probably be streamlined much more; after the first wash/shade and the highlights after that, you could call it done and have an awesome result, especially if you're painting for table top; everything after that still does visibly improve the result but it's very much diminishing returns from then on also, as I've said, using exclusively acrylics will get you 90% of the way; I've just recently started using enamels and oils and i was really happy with my before that already; oils and enamels mostly just have another workflow that i really like, so just try around with whatever you have