Basic advanced function template

Test-Function.ps1

function Test-Function {
	[OutputType([String])]
    [CmdletBinding(
        SupportsShouldProcess=$true,
		ConfirmImpact="None" 		
    )]
    param (
		[Parameter(Position=1, Mandatory=$true, ValueFromPipeline=$true)]
        [ValidateNotNullOrEmpty()]
        [string]$Name
    )
    Begin{
		$formats = @{
			"Begin" = "Begin {0}...";
			"Process" = "...processing {0}...";
			"End" = "...ending {0}";
		};
    	Write-Verbose -Message ($formats.Begin -f $MyInvocation.MyCommand);
    	$date = Get-Date;
    } Process {
    	Write-Verbose -Message ($formats.Process -f $MyInvocation.MyCommand);
    	if ($pscmdlet.ShouldProcess($Name)) {
			return "Welcome to Hello World $Name on $date";
		}
    } End {	
    	Write-Verbose -Message ($formats.End -f $MyInvocation.MyCommand);
    }
}

"Bob", "Mary" | Test-Function -WhatIf
"Bob", "Mary" | Test-Function -Confirm
"Bob", "Mary" | Test-Function -Verbose

Test-Function -Name "Bob"