Do not make a new forum just for the purpose of creating and posting a stylesheet
Its fine to create a test forum for your own use to create styles but do not make a new forum for every stylesheet you create. 

There are other ways to handle this:

1.  Post a screenshot (use thumbnail images) of the stylesheet.   How to Post Thumbnails
 
2.  Use http://www.styleyourforum.com/ 
What is StyleYourForum.com?
StyleYourForum iis provided by SMF for FREE as a place where style creators can upload their creations.

All style images are hosted on styleyourforum.com.   You do not have to worry about bandwidth issues on your own personal hosting account.  Even the images in the css file are automatically hosted.

A Preview forum is created so you  use THAT Preview link to post here as a Live Demo/Preview of your style.

You can also submit directly to StyleYourForum.com in Manage Styles on your own forum.


IMPORTANT:  Remakes and Conversions
If you do a remake or a conversion of a stylesheet or theme you are required to give credit to the original author of the theme/style and a link back to the original authors site if you have that.   We will delete the stylesheet if credit is not given.

Do NOT remake themes that are Paid themes.   If you do so the thread will be deleted.
Do NOT use copyrited images for your stylesheets.

If you do a stylesheet request for someone please post the stylesheet in the Stylesheet Codes Board http://www.smfsupport.com/support/stylesheet_codes-b7.0/   then give them a link to the thread for it. 
Do not post the stylesheet codes in the Request threads.

The Stylesheet Index
We do not do screenshots/thumbnail images for you for the Stylesheet Index. 
If one is not posted with your Stylesheet Code there will be no thumbnail/screenshot in the Index.
How to Post Thumbnails

thanks!