Tanthalus already mentioned it but, yea keeping your IIIs up should help you keep the DPS high even while moving around, as in, if your AF3 has 3 seconds left, better use B3 to get UI3 for 10 seconds while you reposition yourself (and recover MP). Switch to AF3 if running low on UI3 and still havent found a good spot tho :v (pretty useful for speed runs actually).