Hello! :)
In this Guide i have listed all words you can craft to find your missing letters you need to craft the word you are looking for.

Example: I have EXAPLE and need M so I'll search for M: and scroll down the list until I find the word I need.

B:
D DIE - BORN
M MAIM - MEND - BREAK
N ONE - BOTH
P PALE - BRILLIANT
R REAR - FRONT - BACK
S SELL - BUY
S ISSUE - ABSCOND
T TIE - UNTIE - BILL
T TOP - BOTTOM
W WOE - BLISS
Z OOZE - GUMPTION - DRIBBLE

C:
A ADD - SUBTRACT
A ATE - RECONCILE
F FLY - CONQUER
I ISSUE - ABSCOND
N INANE - FORCIBLE
P PAT - CASTIGATE
P PIY - COMPRISE
R RARE - COMMON
R RIM - MIDST - CIRCUMFERENCE
S SAD - CHEERFUL
W AWE - DISRESPECT
Y EYE - CRITERION

D:
B BOW - DOMINEER
B BUT - SLEND
E EBB - FLOOD
H HEAL - REPORTED
M MAT - DISENTANGLE
N NOON - MIDNIGHT
O OWN - DISOWN
P PAY - DEFAULT
P UP - DOWN
R OR - AND
S SEA - LAND
S SON - DAUGHTER
W AWE - DISRESPECT
Z OOZE - GUMPTION - DRIBBLE

F:
B EBB - FLOOD
S SAD - CHEERFUL
D DEED - REVERSAL - AFFIRMATION
G AGO - FUTURE
N ON - OFF
P PAY - DEFAULT
R RIM - MIDST - CIRCUMFERENCE
R REAR - FRONT
T TO - FROM

G:
A AIM - OVERSIGHT
B BEAU - DELINQUENT - PARAGON
B BOY - GIRL
C CUT - ROUGH
F FOR - AGAINST
M MAT - DISENTANGLE
N NOON - MIDNIGHT
P PAT - CASTIGATE
R ROAR - LANGUAGE
R ROT - GERMINATE
S SEE - IGNORE
S SON - DAUGHTER
T TAKE - GIVE - GET
T EAT - GAWKY
Y EYE - CRITERION - GLANCE
Z OOZE - GUMPTION

H:
A AIM - OVERSIGHT
B BE - VANISH
C CUT - ROUGH
D AID - HINDER
G AGE - YOUTH
S SAD - CHEERFUL
S SON - DAUGHTER
L ILL - HEALTHY
N ONE - BOTH
S US - THEM
W WE - THEY

J:
D DARE - ADJURE
R ROAR - LANGUAGE - JARGON
S SORROW - JOY
S STAID - JAUNTY

K:
G GAG - EVOKE
M MAIM - MEND - BREAK
M MOPE - FRISK
S SHELL - KERNEL
R REAR - FRONT - BACK
T EAT - GAWKY

L:
B BOY - GIRL
D DEED - REVERSAL
E EBB - FLOOD
F FEE - PENALTY
F FUN - TOIL
G GAG - EVOKE - ALLAY
M MAT - DISENTANGLE
M MORE - LESS
N NONE - ALL
P PAY - DEFAULT
R IRE - MILDNESS
S SAD - CHEERFUL
S SEA - LAND
T ATE - RECONCILE
W WOE - BLISS
Y EYE - CRITERION - GLANCE
Z OOZE - GUMPTION - DRIBBLE

M:
B BAR - INSTRUMENT
B BOW - DOMINEER
D IDEA - SUBSTANCE - ANIMAL
N NOON - MIDNIGHT
P PAPA - MAMA
P PIY - COMPRISE
R ROT - GERMINATE
R ERROR - WISDOM
S US - THEM
T TO - FROM
T TOP - BOTTOM
W WOE - BLISS - TORMENT
Y YOU - ME
Z OOZE - GUMPTION

N:
B BAR - INSTRUMENT
B BE - VANISH
B BOW - DOMINEER
D ODD - EVEN
F FLY - CONQUER
F OFF - ON
L ALL - NONE
M MAT - DISENTANGLE
N NEAR - FAR
P PUT - TRANSPOSE
P UP - DOWN
R OR - AND
R ROT - GERMINATE
S SEA - LAND
T OUT - IN
Y YEA - NAY

P:
B BOO - APPLAUD
D AID - HINDER - HELP
F FEE - PENALTY
F FOE - SPOUSE
H HEAL - REPORTED
G GO - STOP
M MAMA - PAPA
N UNION - SEPARATION
P PAN - PRAISE
R ERR - PROSPER
S USE - RENDER - EMPLOY
W AWE - DISRESPECT
Z OOZE - GUMPTION

Q:
B BEAU - DELINQUENT
F FLY - CONQUER
L LOUD - QUIET

R:
A AIM - OVERSIGHT
B BE - VANISH - APPEAR
B BOY - GIRL
B BOW - DOMINEER
C CUT - ROUGH
D DIE - BORN
F FLY - CONQUER
H HEAL - REPORTED
G AGO - FUTURE
M MAIM - MEND - BREAK
M MOPE - FRISK
N ENNUI - ENTERTAINMENT
P PAIN - PLEASURE
P PIY - COMPRISE
P PUT - TRANSPOSE
S SEE - IGNORE
S SON - DAUGHTER
T TO - FROM
W AWE - DISRESPECT
Y EYE - CRITERION

S:
A AIM - OVERSIGHT
B BAR - INSTRUMENT
B BE - VANISH
D ADD - SUBTRACT
F FOE - SPOUSE
F FOR - AGAINST
G GO - STOP
H HE - SHE
M MOPE - FRISK
N NO - YES
N NEED - USELESSNESS
O OWN - DISOWN
P PAT - CASTIGATE
P PIY - COMPRISE
P PUT - TRANSPOSE
R AIR - SEA
W WOE - BLISS

T:
A AIM - OVERSIGHT
B BAR - INSTRUMENT
B BEAU - DELINQUENT
D ADD - SUBTRACT
F FEE - PENALTY
F FOR - AGAINST
F FUN - TOIL
H HEAL - REPORTED
H HEAR - ENTREAT
G GO - STOP
L ILL - HEALTHY
N IN - OUT
P PAY - DEFAULT
R REAR - FRONT
S SON - DAUGHTER
S US - THEM
W WE - THEY
Y EYE - CRITERION
Z OOZE - GUMPTION

V:
A AIM - OVERSIGHT
B BE - VANISH
D ODD - EVEN
G GAG - EVOKE
T TAKE - GIVE

W:
D ADDED - INTRINSIC - BORROWED
F FORM - DESTROY - SPAWN
M MAN - WOMAN
M MEN - WOMEN
N ENNUI - ENTERTAINMENT - WEARINESS
P UP - DOWN
R ERROR - WISDOM
S ISSUE - ABSCOND - SHOW
T EAT - GAWKY

X:
BEG - EXACT

Y:
F FEE - PENALTY
F FOIBLE - ATROCITY
G AGE - YOUTH
L ILL - HEALTHY
M ME - YOU
N NO - YES
R ERROR - WISDOM - FOLLY
S SELL - BUY
S EASE - AGONY
T EAT - GAWKY
W WE - THEY

Z:
IDLE - BUSY - LAZY
NADIR - ZENITH
SPHERE - ZONE