I am grateful to Sigur from Battlebrush Studios
for giving me the tip about Vallejo Metal Medium. This gives a beautiful metallic sheen, just what my Romans needed to make them stand out more.
Originally they were painted in base colours and then dipped in Army Painter Strong Tone Dip. The end result was OK, but nothing special. The metal was rather dull and lifeless. Now with this I can put my army on the table without too much embarrasment.
I just need to learn how to win.