As a professional software engineer, the author can tell you with great conviction that you should take the time to place comments into your procedures. Some of your procedures will be in use for a long time. A few concise comments placed in your procedure will benefit you greatly six months later when you wish to modify it. A few months after you write a poorly commented program or procedure, your memory of it may be dim enough to cause some difficulty in reading your own code. Good commenting is also a courtesy to anyone else who may eventually need to modify your procedure.
To make your command procedures clear, one good approach is to break your procedure down into small units, about 20 lines or fewer per unit. Before each unit, place one or two comment lines that describe in plain language what the unit does. Later, when you must come back to modify the procedure (as always happens), you will not have to spend as much time deciphering what the code does.
The command procedures presented in this book illustrate this guideline.