I'm playing a caster in a setting hack of the Dresden files. I find that it's very easy to get in an unbalance of my Conviction and Discipline skills. If Conviction is too high then I fail my discipline rolls and take backlash (which makes for interesting plots, but I like lasting the scene). If Discipline is higher my rolls are effectively wasted.
What is the optimal ratio of Conviction to Discipline, that generates the most powerful effects without nuking myself?