Signs are shapes and shapes can be looked at from very different angles: therefore, you will agree that some guide lines on how to delineate the signs when matching their shapes to the shapes forming the characters are necessary. Otherwise, in some we cases won't know where a sign starts and where it ends.
Rule 1: character shapes are allocated to form the most complete sign:
Rule 2: first signs chosen are allocated as much character shape as possible.
This rule is in fact an application of rule 1.
Rule 3: Avoid joining of signs at an angle of character shapes.
Rule 4: In principle sign lines must not cross over other sign lines, especially enclosed shapes:
But signs line crossing do occur, when there is no crossing of enclosed shapes and where the "no-crossing" rule will result in the creation of many signs. Examples:
The main exception to rule 4 is the case of five defined characters: 木, 大, 火,七, 戈 :
Conclusion: The codification of Chinese characters according to their morphological aspect --which is their particularity-- is not an exact mathematical science because characters are not geometrical figures! Hence, we must keep some flexibility in mind: the numerous advantages of CangJie warrant it.
knowing the rules of completion (rule1 & 2), the manner of "joining" adjacent signs (rule3), and of non-crossing of signs lines (rule 4 and exceptions) we are now properly armed to use our the signs (main and secondary) and the rules of order, to practice input with many simple characters.
Action: now is the time for practice! Download the exercises of carefully selected characters from Chapter 2 of the CangJie Method book. Print and proceed the same way you did for the main signs. Take your time practice: you are building your base! Don't forget to do the same exercise but as "reverse engineering": you will improve your Chinese vocabulary and reading ability.
Then you will be just right mature to face any character, simple or complex, and dismantle it and to extract the signs -maximum of 4 or 5 that compose the code.
Next Step 6: the rules of selections of signs