Take What You Can Get
You don't have to re-invent the wheel. Sometime a theme, module, or core will provide you with some great little "additions" you can use to improve your site. In this example, I am going to share a little cut and paste I did to improve (IMHO) my webform.
Here's how it looked before
[inline:formbefore.png]
You'll notice that I used the header section of the webform to let the end user know that the form has some required fields, and that those fields are designated by the star (asterisk).
Good WebDeveloper :)
Let's take this one more step.
Let's put the star (asterisk) in our instructions.
You could just put a asterisk, that might work.
You could add a span class, goto your css color it.
Or... use what the page is giving you and take it.
Here's the Improvements
Use firebug and inspect the required field asterisk.
Copy the HTML code that it is outputting.
[inline:firefoxtake.png]
Paste the code into the instruction area of your form.
[inline:addhtml.png]
Done
[inline:formafter.png]
This method has the added benefit that it is consistent with the entire site. If you change themes, add a module, whatever... because the mark-up is consistent, you'll probably be in good shape.

Comments
Images not showing.