Yes. So far I have tried only to increase magenta in order to get more contrast. But then I had to make a couple of new testprints again.
For example if 10 magenta equals xx percent more exposure then it would be easier.
Do you recommend to by graded filters instead?
I have a chart that I use to determine the different paper grades. It's included in with all Ilford paper. It has roughly the same density for every filter setting. It works pretty well for me. There are methods of fine tuning those settings, but this should be a good starting point.