Here is a little list of possibilities. Two different tunings in two different keys using the same strings. If you use medium gauge strings on a standard scale length, tuning down will be easier on your neck. The numbers are the major scale tones.
1) Standard Strings: EADG
Tune down: DGDG (Key of G 5151)
Tune down: DADf# (Key of D 1513)
2) Standard Strings: ADGB
Tune down: GDGB (Key of G 1513)
Tune down: ADF#A (Key of D 5135)
3) Standard Strings: DGBE
Tune down: DGBD (Key of G 5135)
Tune down: DF#AD (Key of D 1351)
Enjoy, you Tiger's Blood drinking Warlocks!
Thank you Eric for your comment. Ya, tuning lower not only sounds cool, but definitely takes a lot of stress off of the CBG neck. This is a good approach when stringing and tuning older vintage guitars too that don't have truss rods. Enjoy your practice, Keni Lee