Note: Install NoScript and Cookie Whitelist, With Buttons and always keep them blocking everything while browsing Eepsites. Malicious scripts and cookies can compromise your anonymity.
For additional anonymity look at the privacy protecting add-ons on the Firefox page.
Install the Firefox add-on QuickProxy. After the add-on installs restart Firefox. After Firefox restarts, open your proxy settings by opening the "Edit" tab and going to "Preferences". Select the "Advanced" tab. What you see should look like the image below: