I used to think the Tamiya weathering kits was all you needed, until I got the doc o’briens set from micromark goes on easy and you can either do it as a powder or mix with water depends on your preference so far I have done it in powder form, but be careful a little goes along ways, and follow there instructions about mixing with liquids.
like you i have used tamiya powders and started using pastels. i just started working with oil pin washes over acrylic paint. i have some doc o’briens and will try them on my next build.
I have been using Mig and AK-Interactive stuff