SBSettings is a replacement for BossPrefs. It moves your important toggles directly into Springboard where they are always available instantly even while other apps are running.
BigBoss has provided a guide which will explain what each element is that can be themed, where the theme folders are expected to go, and provides some screenshots. It also has a link to the default theme with all the files expected in their proper locations so that you can make your theme mimick this layout.
If you think you have created a really good theme you can submit it for inclusion on the BigBoss Repository.