Using the small soft brush I carefully paint the wooden plank of the sleeper with Burnt Umber, or any other medium to earthy brown colour. I take care to fully cover and try not to bleed onto the "metal work". This is one of the stages where care is needed.

Using the small soft brush i carefully paint the sleeper chairs with Burnt Sienna, or any other rusty, reddy-brown colour. I take care to fully cover and try not to bleed onto the already painted sleeper wood. This is one of the stages where care is needed.

I use a tiny blob of black acrylic, with a splash of IPA and some drips of soapy water to make a thin black paint "wash". The wash should have just enough pigment in it darken the colour of what ever is painted with it. This is hard to describe, it kind of comes with experience. Better to be too little and then wash it again once the first wash has dried than go to heavy at this point.
I use the small soft brush allow the wash to run all over the wooden plank of the sleeper. Mop up any excess with a dry paint brush, paper towel or sponge. Although we want the wash to run into all the crevices we don't want it pooling anywhere en mass. The IPA and soap helps break the surface tension and get the pigment down into the wood grain effect scratched on with the course abrasive paper.

Use a tiny blob of Black and Burnt Umber acrylic, with some drips of soapy water to make a thin dark brown paint "wash". No need for the IPA here.
I wash the sleeper chairs, and again I prefer two or more coats of "too thin" than one coat of too thick!

I use the (old) flat brush with stiff bristles I introduce a small amount of the grey paint, and then using a paper towel, remove practically all of the paint. I test on a clear bit of cardboard, paper or paper towel, until only the tiniest amount of pigment is left on the paper. I lightly tickle the sleeper plank with so the pigment gets picked up by the corners and the raised grain effect I "sanded" into it.

With this going gentle is always the best approach. It is better to put on far less and slowly add more, because it can be easy to spoil the good work already done, with a big blob of paint now. Ask me how I know?!! The look I try to achieve is that of a sun-bleached plank. Although the planks would generally be dark from years applications of creosote, high parts will dry out slightly and become bleached, especially for non-well-maintained items.

I am not to fussed if the sleeper chairs get a bit of grey at this point either.

Using the same (old) flat brush with stiff bristles, I follow a similar approach to the highlight for the sleeper plank, only this time I uses rusty oranges or reds.