It is general practice that we deliver wsp and powershell script to install it.
it is good practice to log whatever we show in screen to file so that it will be easy for sharepoint admin to send the result of installation.
# Set Execution Policy
$date = Get-Date
#read parameters from command line
$CurrentDir= Split-Path -parent $MyInvocation.MyCommand.Definition
$timeStamp = (Get-Date).ToString("yyyyMMddhhmmss")
$logFile = $CurrentDir+ "\install_" + $timeStamp + ".log"
start-transcript -path $logFile -noclobber
#add this at end of script
#this is to show stop-transcript
$CurrentDir will get installation folder. Start-Transcript is powershell command to copy whatever message printed to console to file provided in parameter.
You have to place your installation script between start and stop transcript commands and everytime you execute the script, it will generate a separate log file that will have all details.