This sort of thing is a matter of preference really but given that there are a few threads pertaining to "unix script best practices" I thought it would be useful to post a script stub to promote just that - a best practice.
#!/usr/bin/ksh
#
# SCRIPT: NAME_of_SCRIPT
# AUTHOR: AUTHORS_NAME
# DATE: DATE_of_CREATION
# REV: 1.1.A (Valid are A, B, D, T and P)
# (For Alpha, Beta, Dev, Test and Production)
#
# PLATFORM: (SPECIFY: AIX, HP-UX, Linux, Solaris
# or Not platform dependent)
#
# PURPOSE: Give a clear, and if necessary, long, description of the
# purpose of the shell script. This will also help you stay
# focused on the task at hand.
#
# REV LIST:
# DATE: DATE_of_REVISION
# BY: AUTHOR_of_MODIFICATION
# MODIFICATION: Describe what was modified, new features, etc-
#
#
# set -n # Uncomment to check your syntax, without execution.
# # NOTE: Do not forget to put the comment back in or
# # the shell script will not execute!
# set -x # Uncomment to debug this shell script (Korn shell only)
#
##########################################################
########### DEFINE FILES AND VARIABLES HERE ##############
##########################################################
##########################################################
############### DEFINE FUNCTIONS HERE ####################
##########################################################
##########################################################
################ BEGINNING OF MAIN #######################
##########################################################
# End of script