Digital BW, The Print

Hello,
I just got the MIS VM inks for my Epson 1200 and am trying to figure out 
general guidelines on how to adjust the curves for my system. I know that the 
blue ink is increased by adding more magenta, midtones by adding more cyan 
and light tones by adding more yellow at the appropriate place on the curve. 
Where I get more confused is on what's the best way to compensate with other 
inks when you change the proportion of one ink. For example, I wanted a 
warmer print in the midtones so I increased green, but as a result that area 
of the wedge also became lighter. Should I add more cyan or should I modify 
the transfer function or is there something else I should do? 

Thanks,

Marketa Ebert