Thought this might be a useful note
While enhancing my wikifu, I came across this.
Creating, editing and using templates
You start a new template in the same way you would start a normal page. The only difference is that its title must start with Template:
(eg. Template:templatename)
Once you have made the template, you can add {{templatename}} to the pages you want to use it on. Every page using this template will get the same boilerplate text, each time a user visits it. When the template is updated, all pages containing the template tag will automatically be updated.
Alternatively, you can add {{subst:templatename}} to the pages you want to use the boilerplate text on. The system will fetch a one-time copy of the template text and substitute it into the page, in place of the template tag. If anyone edits the template afterwards, pages that used the subst: keyword will not be updated. Sometimes that's what you want.
If the template you want to edit looks like {{foo}}, you would go to Template:foo to edit it. To get there, type in the URL to your address bar, search for it, or make a link in the sandbox and click on it.
Once you are there, just click "edit" or "edit this page" and edit it in the same way you would any other page. You can add anything you would add to a normal page, including text, images and other templates. Please be aware that your edit might affect many pages, so be cautious.
Also use
{{Cleanup}} To insert standard "clean this up" boilerplate text.