Mach,
The trick is when PNF calls "Flap setting...." during the before take off checklist, the PF can call "Config....", naming the flap setting with reference to:
1. E/WD (engine warning display) to show actual flaps position,
2. TOLD (data card) to show planned/calculated flaps position,
3. MCDU to show flap position entered into the "box",
4. Flap lever to show flap position selected.
I can't find this flow written anywhere, but someone kindly passed it on to me, & it could pick up several potential problems. Having said that, it is hard to stay disciplined on cumulative multi sector days, as energy levels are impacted.