Don't just paste the template tags at the literal beginning and end of your template code--making too much of your template editable can lead to mistakes down the road. Instead, find the smallest level of HTML containers (either a table or a div) that contains everything that might change in each blast. In other words, try not to capture your title banner or unsubscribe information within the editable template region--that stuff won't be changing often, and you only want to worry about the parts that can change.
If you have a graphic that stays the same on every email, that should be protected in the template, so keep it outside of the TemplateBeginEditable and TemplateEndEditable tags:
<!-- TemplateBeginEditable name="content" -->
<!-- TemplateEndEditable -->
If you have a side bar that changes, that must be inside of the TemplateBeginEditable and TemplateEndEditable tags.
There are two possible pit falls to keep in mind when choosing where to put your TemplateBeginEditable and TemplateEndEditable tags:
1. There can be only one set of the tags per template. Having more than one set will cause undesired results.
2. You must ensure that a table (or any other tag) isn't broken up in both editable and protected areas of the template. You can have a table start before and end after the protected area (in other words, be outside of the TemplateBeginEditable and TemplateEndEditable tags) as long as there are no trs or tds of that table in the editable area (inside of the TemplateBeginEditable and TemplateEndEditable tags).
Template tags showing up in your preview pane? Uh oh!
Are you getting reports that the template tag code is showing up in the preview pane of your supporters' email programs? Unfortunately there's no universal method that all email programs use for displaying preview text. Blogger Ian Hoar wrote an article about this. Check it out for some tips on creating "fake" preview text using hidden CSS code, but as always, test your email blasts on various browsers and email programs before deploying them!