How to set up a message template?

I can't seem to find this documented, perhaps I've overlooked it.
I want to set up message templates, without using HTML, for messages I will be using often.
Intuitively, I thought I'd be able to keep a message in the Drafts folder, but the drafts disappear once I hit send.
Google searches return html templates for sale, and searches here return questions about "stationary", neither of which are helpful to me.
Any tips, tricks or workflow examples would be appreciated!
Jake