Suggestions for Practicing Half-steps in Three Hole Draw?

["Bob McGraw" <rmcgraw@xxxxxxxxxxxx>]

I've been trying to improve my ability to play the  half-step bends in
three-hole draw;I want to make them sound as much like "regular" notes as
possible.

I've been playing them as [what I believe are called] long tones;in other
words,hitting each note and attempting to hold it as long as
possible,meanwhile attempting to make it sound as good as possible.An
immediate problem is that each note tends to "waver" a bit and I can't play
the notes as loudly as I want.

Can anyone suggest specific things I can do to eliminate this "waver" and
increase my volume?I mean aside from simply playing them as long tones? I am
trying to accomplish the bending with my diaphragm,and am trying to allow
the bending to happen as far back in my throat[diaphragm?You know what I
mean?] as possible.

Also, are there any other suggestions for exercises for improving these
half-step bends?
WVa Bob
P.S.A fun thing I've been doing for this is playing the head to Miles
Davis's "All Blues." It's pretty easy to figure out,but it really calls for
precision!