A good start always is, leaving away from published presets:
• Corrections above ca. 2000 Hz, specially high-Q and/or low gain.
• Boost corrections with high Q-factor (narrow bandwidth).
Reasons:
• The measurement target curves are extremely smoothed, low detailed.
• The measurement microphones (with pinnae and ear canal) are a coarse average of a multitude of human beings and therefore don’t represent YOUR personal ear.
• Small variations of positioning on the head largely affect a measurement result. For this reason again a lot of smoothing or averaging of multiple measurements is used.
But - such an average doesn’t represent any single measurement.
The pinnae (outer ear and ear canal) have influence on the frequency response from ca. 1000 Hz and up - the higher the frequency the more, with variations of up to +/- 20 dB!
Measurements below ca. 2000 Hz can be trusted and are valid.
So, trying to correct more detailed than the headphones are measured must fail and results in strange colorations instead of corrections.
For the treble, use a wide-band (low-Q) shelf filter, plus maybe one wide-band peaking filter, and adjust solely to taste.