Here are some tips to help solve random substitution ciphers or cryptograms:
The most common letters in English are (in rough order) E, T, A, O, I, N, S, H, R, D, L, U. This means that if your code has more B's than any other letter, B could stand for the plain text letter E.
Single-letter codewords must be either A or I.
Two-letter codewords which occur often in the code are probably IN, OF, TO, IS, AN, ON, BY, BE, IT or OR
Three-letter codewords which occur often are probably THE, YOU, ARE, AND, ANY, BUT, NOT, or CAN. If they have a double letter they are probably ALL, TOO or SEE.
Single code letters after an apostrophe (') is probably 's, but could also be 't (isn't) or 'm (I'm). Also look out for 've, 'll, 're.
Look for common patterns at the end of words, which could be -ED, -ING, -S, -TION. Many words end in -E.
Double letters can't be AA, HH, II, JJ, KK, QQ, UU, VV, WW, XX or YY
Don't be scared to guess to fill in gaps in words!! e.g. cXmmQnicWBiXn = communication. Now you can fill in the correct letters wherever you see X, Q, B or W in the code. If it doesn't work somewhere else in the code, perhaps your guess was wrong, so try again.
Look out for names, places and common words which might occur in the code, such as the name of your Patrol, place names, or the name of the person who gave you the code.
Look out for common phrases at the beginning of sentences. For instance, instructions often have sentences starting "YOU MUST ..." or "GO TO THE ...", and an ending such as "XQQE UOPZ!", which could be "GOOD LUCK!" Famous quotations often end with the name of the person quoted.