Pre test, I follow the Full Frontal training plan.
During the test I stick to level mode for NM and MAP efforts, following those I switch to ERG mode and set to 110% of FTP, couple of minutes in decide how that feels and may increase up or down, normally down! I find it much easier having a number to target rather than go by just feel, but then everyone is different! Oh and back to level for the AC effort (man that hurts).