Years of bug writing experience has been distilled for your reading pleasure into the Bug Writing Guidelines. While some of the advice is Mozilla-specific, the basic principles of reporting Reproducible, Specific bugs, isolating the Product you are using, the Version of the Product, the Component which failed, the Hardware Platform, and Operating System you were using at the time of the failure go a long way toward ensuring accurate, responsible fixes for the bug that bit you.
The procedure for filing a test bug is as follows:
Go to Landfill in your browser and click Enter a new bug report.
Select a product - any one will do.
Fill in the fields. Bugzilla should have made reasonable guesses, based upon your browser, for the "Platform" and "OS" drop-down boxes. If they are wrong, change them.
Select "Commit" and send in your bug report.
Try to make sure that everything said in the summary is also said in the first comment. Summaries are often updated and this will ensure your original information is easily accessible.
You do not need to put "any" or similar strings in the URL field. If there is no specific URL associated with the bug, leave this field blank.
If you feel a bug you filed was incorrectly marked as a DUPLICATE of another, please question it in your bug, not the bug it was duped to. Feel free to CC the person who duped it if they are not already CCed.