Adding yarn then immediately bind off

[ABC's Mom]

My title may sound a bit weird, but here's what my question is.
I am to the point on the back of a sweater where I'm starting the shaping for the neck. The pattern says: knit in pattern to marker, add yarn and BO between markers....
My question is how is the best way to add the second ball of yarn and then immediately bind off the stitches?

[suzeeq]

Oh that's for the neck shaping. Just start using