I've been trying to replicate rust and aging techniques for years, and so far i'm still perfecting it, this I done all by trying and trying allover without any foreign help (maybe that's why it took me so long ) anyway, as for rust I'm getting close to real, but for paint aging and streaks I'm still far from the perfect thing.
My first attempts were done on these rolling stock model.
as for aging it leaves a bit to desire though
lately I tried the rusting technique again, and this is the result
I still need more practice, but maybe you can help me out in improving. I still have to age the paint and fix some details on this, so I will be posting a couple more photos to show you my end result so you can tell me where can I improve.