After some amount of playing, I've finally started to get the hang of editing message workflow templates (Administer CiviCRM, Communications, Message Templates, System Workflow Messages) to include organization specific messages or additional tokens (e.g. contact id). Trouble is, as near as I can tell, there's no previewer for the changes you make (e.g. wysiwyg editing). This makes it difficult to see what changes you've made because the only way to see your changes, seems to be by going through the workflow process. For example, to see if my offline events registration confirmation shows my changes in the right place, I need to create an event, fill in every required field, register someone, and so on. Over and over until things look right in the emailed confirmation.
And so, is there another way to just preview the changes without jumping through all those additional hoops?