Just modify "TITTLE" and "NOTIFICATION" for your desired texts.
powershell [Reflection.Assembly]::LoadWithPartialName("""System.Windows.Forms""");$obj=New-Object Windows.Forms.NotifyIcon;$obj.Icon = [drawing.icon]::ExtractAssociatedIcon($PSHOME + """\powershell.exe""");$obj.Visible = $True;$obj.ShowBalloonTip(100000, """TITLE""","""NOTIFICATION""",2)>nul
The last number, before the last closing parenthesis, means the type of notification.
1 - Information
2 - Alert / Warning
3 - Error
Edit1:
You can use Powershell functions/variables to improve your notifications.
powershell [Reflection.Assembly]::LoadWithPartialName("""System.Windows.Forms""");$dateTime=Get-Date -Format HH:mm; $obj=New-Object Windows.Forms.NotifyIcon;$obj.Icon = [drawing.icon]::ExtractAssociatedIcon($PSHOME + """\powershell.exe""");$obj.Visible = $True;$obj.ShowBalloonTip(100000, """Hey """ + $env:UserName, """It's """ + $dateTime + """ drink some water!""",1)>nul