off the top of one's head
extemporaneously
unprophetically
on the hoof
pro forma
perfunctorily
inofficiously
unpremeditatedly
involuntarily
nonjudgmentally
modus operandi
routine
nonconceptually
uninquisitively
uncleverly
unevocatively
unsystematically
unconscious
methodistically
undistinguishedly
unorthographically
unabidingly
idly
undisputatiously
nondeviantly
observantly
nonintentionally
unpunctually
undividedly
undiscernedly
observingly
unabashedly
expeditiously
unadvisedly
unimaginatively
sentiently
unstraightforwardly
deliberately
extemporaneous
measuredly
unpurposively
indeliberate
intuitive
unmagnanimously
unexpertly
univocally
unregretfully
unhamperedly
casually
noncontingently