1. Boltgun metal applied over the black undercoat. Do not worry too much about blacklining, but keep it neat and thin the paint if necessary to get a good coverage which is essential for the following stages:
2. The armour is washed/glazed using a mix of Tamiya Clear Orange, Chaos Black, a little Chestnut ink.
The wash is thinned with water and a drop of dish soap is added to make the wash flow easier and the coverage should be something between a wash and a glaze (hard to describe really).
If necessary add a second wash applying it to the detail that need a little extra shading:
3. The armour is highlighted with thinned down Mithril silver. Thinning the paint makes it possible to "feather" or blend the highlights.
In practice what I do is to add a slightly transparent highlight and then reinforce it with a second highlight for instance on the very edge of the armour plating. Rivets and the like are highlighted as much as possible: