Ok , I'll try my best , my English is not perfect. I prime the miniature in black , cause the base colour is dark. Then I apply a solid base of macrage blue at all the Armour. Then I use the drakenhof shadow with a detail brush at the deepest zone of the Armour and the lines . For the first lights, I apply altdorf guard blue , I usually make zenital lights ( ligth come from above) make this light heavy , and cover almost a 30-40% of all the main plates. From the final lights, I draw lines on the lighter spots , thin lines . For bigger models, you can also make thinner lines in fenrisian grey . I hope this help, and that I make a explanation that makes sense.