I use my pointer finger to bar the top 3 strings and keep my ring finger planted on the
D-string 11th fret.
[ Tab from: http://www.guitaretab.com/o/oar/273065.html ]
e|-----------------------------9---------|
B|--------------10------9--------12------|
G|------9----9-----9------9--------------|
D|---11---11---------11-----11-----------|
A|---------------------------------------|
E|---------------------------------------|
e|--------------------------------------------|
B|--------------10------9-------10p9----------|
G|------9----9-----9------9---------11p9------|
D|---11---11---------11-----11----------------|
A|--------------------------------------------|
E|--------------------------------------------|
Repeat