I use water extensively on my minis. The key for me is not covering every section of the mini with a successive coat.
1/ Start dark.
2/Leaving the crevices dark, pick out the details with a broad base colour.
(2b)If you want to go nuts, using watered down paint, paint "half" of each section with the next colour in the chain but while its wet step the colour up the further from dark you go (You could use this step at step 2 if you don't want to spend the time).
3/Last apply a targetted highlight but don't try to cover the previous colour, just hit sharp edges or corners with "dots" of paint.
In 6mm you don't need to hit all parts of the mini to make it effective.
Hope these are a clear enough picture to get the idea.
The lower half of the main banner-bearer chest plate and the other one's leg greaves show what I'm trying to say best.
Anyway, hope this helps.
