[Adrian Schneider]

I always go for compliance.

You can save yourself some work if you install Web Developer toolbar for Firefox, so you can right click > submenu > validate local HTML (as you see it).

If you write HTML very clearly (indent properly, use whitespace to help readability), then 90% of your errors you'll catch before even saving. For more complex fixings, you can create a barebones page, and then paste your template into it to test it independently.

Some editors also show tag pairings (I use Eclipse) so when I click on an opening tag, it will highlight the closing tag assuming some validity in the code. Compare this with indentation, and you can quickly find incorrectly nested tags.

Once you get really proficient with CSS, the markup becomes so simple validation is rarely an issue. It's all the nested tables that can make it tricky.