Desi, tsk tsk...
F: Fuel on correct tank, fuel pressure correct, fuel flow correct, contents indicating as expected, contents sufficient, tanks in balance, pump off.
Radio: No 1 frequency on current ATC - standby frq on next expected. No 2 frq on 121.5 if not being used for ATIS or company; Volumes set correctly, both receiving. Transponder, correct code, interrogating; set sby, A or C as req. VOR's both tuned to correct frq and re-identify, warning flags away; ADF, tuned correctly, identified, sensible indication if within range; DME tuned, set to correct NAV option, re-identify, groundspeed and distance fit the metal picture; RNAV set to correct mode, data rechecked.
E: Engine; Carb heat on, RPM drop as expected; T's & P's good; Mixture set; Suction (many miss that); Ammeter (many miss that too); Carb heat off again. RPM as required.
D: Direction indicator synchronised, correct heading, heading bug set correctly, setting knob free to turn (not "caged").
A: Altimeter: Correct settings in Kohlsman windows of BOTH altimeters. Differential matches mental picture. Correct RPS set into number 2 altimeter; correct QNH, QFE or QNE set into number 1. Indicated level is appropriate for direction being flown; both altimeters indicate safe clearance from MSA.
FREDA leaves no spare letters for airframe icing, pitot icing, navigation lights....or multitudes of other things.
What else have I missed?? Or what have I done, that I shouldn't??